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Final Jeopardy

Normally Random - 100

Answer

In a population of students, the number of calculators owned is a random variable X with

P(X = 0) = 0.2, P(X = 1) = 0.6, and P(X = 2) = 0.2. The mean of this probability distribution is

(a) 0. (b) 2.(c) 1. (d) 0.5.(e) The answer cannot be computed from the information given.


Answer


P(X = 0) = 0.2, P(X = 1) = 0.6, and P(X = 2) = 0.2. The variance of this probability distribution is

(a) 1. (b) 0.63.(c) 0.5. (d) 0.4.(e) The answer cannot be computed from the information given.


Answer

A smooth curve which approximates the shape of a histogram and describes the overall pattern of a distribution is called

(a) a stemplot(b) a Normal probability plot(c) a destiny curve(d) a density curve(e) none of the above


Answer

The following graph is a Normal probability plot for the amount of rainfall (in acre-feet) obtained from 26 randomly selected clouds that were seeded with silver oxide. Which of the following statements about the shape of the rainfall distribution is true?

(a) The distribution is Normal.(b) The distribution is approximately Normal.(c) The distribution is roughly symmetric.(d) The distribution has no potential outliers.(e) The distribution is skewed.


Answer

The distribution of the heights of students in a large class is roughly Normal. Moreover, the average height is 68 inches, and approximately 95% of the heights are between 62 and 74 inches. Thus, the standard deviation of the height distribution is approximately equal to

(a)2 (b) 3 (c) 6

(d) 9 (e) 12


Answer

If a store runs out of advertised material during a sale, customers become upset, and the store loses not only the sale but also goodwill. From past experience, a music store finds that the mean number of CDs sold in a sale is 845, the variance is 225, and a histogram of the demand is approximately Normal. The manager is willing to accept a 2.5% chance that a CD will be sold out. About how many CDs should the manager order for an upcoming sale?

(a) 1295 (b) 1070 (c) 935 (d) 875 (e) 860

Normally Random - 100 Answer


P(X = 0) = 0.2, P(X = 1) = 0.6, and P(X = 2) = 0.2. The mean of this probability distribution is

(a) 0. (b) 2.(c) 1. (d) 0.5.(e) The answer cannot be computed from the information given.



P(X = 0) = 0.2, P(X = 1) = 0.6, and P(X = 2) = 0.2. The variance of this probability distribution is

(a) 1. (b) 0.63.(c) 0.5. (d) 0.4.(e) The answer cannot be computed from the information given.


A smooth curve which approximates the shape of a histogram and describes the overall pattern of a distribution is called

(a) a stemplot(b) a Normal probability plot(c) a destiny curve(d) a density curve(e) none of the above


The following graph is a Normal probability plot for the amount of rainfall (in acre-feet) obtained from 26 randomly selected clouds that were seeded with silver oxide. Which of the following statements about the shape of the rainfall distribution is true?

(a) The distribution is Normal.(b) The distribution is approximately Normal.(c) The distribution is roughly symmetric.(d) The distribution has no potential outliers.(e) The distribution is skewed.


The distribution of the heights of students in a large class is roughly Normal. Moreover, the average height is 68 inches, and approximately 95% of the heights are between 62 and 74 inches. Thus, the standard deviation of the height distribution is approximately equal to

(a)2 (b) 3 (c) 6

(d) 9 (e) 12


If a store runs out of advertised material during a sale, customers become upset, and the store loses not only the sale but also goodwill. From past experience, a music store finds that the mean number of CDs sold in a sale is 845, the variance is 225, and a histogram of the demand is approximately Normal. The manager is willing to accept a 2.5% chance that a CD will be sold out. About how many CDs should the manager order for an upcoming sale?

(a) 1295 (b) 1070 (c) 935 (d) 875 (e) 860

Biometric Regression - 100Biometric Regression - 100

Answer

The following are resistant:

(a)Least-squares regression line(b)Correlation coefficient(c)Both (a) and (b)(d)Neither (a) nor (b)(e)It depends


Answer

In a large population of college students, 20% of the students have experienced feelings of math anxiety. If you take a random sample of 10 students from this population, the probability that exactly 2 students have experienced math anxiety is

(a) 0.3020. (b) 0.2634.(c) 0.2013. (d) 0.5.(e) 1.


Answer

A basketball player makes 70% of her free throws. She takes 7 free throws in a game. If the shots are independent of each other, the probability that she makes the first 5 and misses the last 2 is about

(a) 0.635.(b) 0.318.(c) 0.015.(d) 0.49.(e) 0.35.


One concern about the depletion of the ozone layer is that the increase in ultraviolet (UV) light will decrease crop yields. An experiment was conducted in a green house where soybean plants were exposed to varying levels of UV, measured in Dobson units. At the end of the experiment the yield (kg) was measured. The least-squares regression line is the line that

(a) minimizes the sum of the squared differences between the actual UV values and the predicted UV values. (b) minimizes the sum of the squared residuals between the actual yield and the predicted yield. (c) minimizes the sum of the squared differences between the actual yield and the predicted UV. (d) minimizes the sum of the squared residuals between the actual UV reading and the predicted UV reading. (e) minimizes the total variation in the data.

Answer


One concern about the depletion of the ozone layer is that the increase in ultraviolet (UV) light will decrease crop yields. An experiment was conducted in a green house where soybean plants were exposed to varying levels of UV, measured in Dobson units. At the end of the experiment the yield (kg) was measured. A regression analysis was performed with the following results: Which of the following is correct? (a) If the UV reading increases by 1 Dobson unit, the yield is expected to increase by 0.0463 kg. (b) If the yield increases by 1 kg, the UV reading is expected to decline by 0.0463 Dobson units.(c) The estimated yield is 3.98 kg when the UV reading is 0 Dobson units. (d) The predicted yield is 4.3 kg when the UV reading is 20 Dobson units. (e) None of these

Answer

Mr. Nerdly asked the students in his AP Statistics class to report their overall GPAs and their SAT Math scores. The scatterplot below provides information about his students’ data. The dark line is the LSRL for the data, and its equation is y=270.45+109.42x. Which of the following statements about the highlighted point is FALSE?

(a) This student has a GPA of 2.9 and an SAT Math score of 670.(b) If we used the LSL to predict this student’s SAT Math score, we would make a prediction that is too low.(c) This student’s residual is –82.23.(d) Removing this data point would cause the correlation coefficient to increase.(e) Removing this student’s data point would increase the slope of the LSL.


Answer

Biometric Regression - 100 AnswerBiometric Regression - 100 Answer

The following are resistant:

(a)Least-squares regression line(b)Correlation coefficient(c)Both (a) and (b)(d)Neither (a) nor (b)(e)It depends


In a large population of college students, 20% of the students have experienced feelings of math anxiety. If you take a random sample of 10 students from this population, the probability that exactly 2 students have experienced math anxiety is

(a) 0.3020. (b) 0.2634.(c) 0.2013. (d) 0.5.(e) 1.


A basketball player makes 70% of her free throws. She takes 7 free throws in a game. If the shots are independent of each other, the probability that she makes the first 5 and misses the last 2 is about

(a) 0.635.(b) 0.318.(c) 0.015.(d) 0.49.(e) 0.35.


One concern about the depletion of the ozone layer is that the increase in ultraviolet (UV) light will decrease crop yields. An experiment was conducted in a green house where soybean plants were exposed to varying levels of UV, measured in Dobson units. At the end of the experiment the yield (kg) was measured. The least-squares regression line is the line that

(a) minimizes the sum of the squared differences between the actual UV values and the predicted UV values. (b) minimizes the sum of the squared residuals between the actual yield and the predicted yield. (c) minimizes the sum of the squared differences between the actual yield and the predicted UV. (d) minimizes the sum of the squared residuals between the actual UV reading and the predicted UV reading. (e) minimizes the total variation in the data.


One concern about the depletion of the ozone layer is that the increase in ultraviolet (UV) light will decrease crop yields. An experiment was conducted in a green house where soybean plants were exposed to varying levels of UV, measured in Dobson units. At the end of the experiment the yield (kg) was measured. A regression analysis was performed with the following results: Which of the following is correct? (a) If the UV reading increases by 1 Dobson unit, the yield is expected to increase by 0.0463 kg. (b) If the yield increases by 1 kg, the UV reading is expected to decline by 0.0463 Dobson units.(c) The estimated yield is 3.98 kg when the UV reading is 0 Dobson units. (d) The predicted yield is 4.3 kg when the UV reading is 20 Dobson units. (e) None of these

Mr. Nerdly asked the students in his AP Statistics class to report their overall GPAs and their SAT Math scores. The scatterplot below provides information about his students’ data. The dark line is the LSRL for the data, and its equation is y=270.45+109.42x. Which of the following statements about the highlighted point is FALSE?

(a) This student has a GPA of 2.9 and an SAT Math score of 670.(b) If we used the LSL to predict this student’s SAT Math score, we would make a prediction that is too low.(c) This student’s residual is –82.23.(d) Removing this data point would cause the correlation coefficient to increase.(e) Removing this student’s data point would increase the slope of the LSL.


Relational Design - 100

Answer

The percent of cars listed in the table with 4-cylinder engines that are made in Germany is

(a) 10.5%.(b) 21%.(c) 50%.(d) 80%.(e) 91%.

Relational Design - 200From the table we might conclude that

(a) there is clearly no relation between country of origin and # of cylinders. (b) the correlation between country of origin and # of cylinders is likely to be about 0.5. (c) a regression line fitted to these data would probably have a negative slope. (d) there is evidence of some relation between country of origin and number of cylinders. (e) the United States has far more cars than any of the other countries.

Answer


Answer

Control groups are used in experiments in order to

(a) control the effects of outside variables on the outcome.(b) control the subjects of a study to ensure that all participate equally.(c) guarantee that someone other than the investigators, who have a vested interest in the outcome, controls how the experiment is conducted.(d) achieve a proper and uniform level of randomization.(e) None of the above.


Answer

What electrical changes occur in muscles as they get tired? Student subjects hold their arms above their shoulders as long as they can. Meanwhile, the electrical activity in their arm muscles is measured. This is:(a) an observational study.(b) an uncontrolled experiment.(c) a randomized comparative experiment.(d) a matched pairs design.(e) impossible to describe unless more details of the study are provided.


Answer

The Community Intervention Trial for Smoking Cessation (COMMIT) asked whether a community-wide advertising campaign would reduce smoking. The researchers located 11 pairs of communities that were similar in location, size, economic status, and so on. One community in each pair participated in the advertising campaign and the other did not. This is(a) an observational study.(b) a matched pairs experiment.(c) a completely randomized experiment.(d) a block design.(e) impossible to answer unless more details of the study are provided.

The following two-way table categorizes suicides committed in a particular year by the sex of the victim and the method used.

Method Male FemaleFirearms 13,959 2,641Poison 3,148 2,469Hanging 3,222 709Other 1,457 690

Which of the following statements is consistent with the table? (a) There is absolutely no evidence of a relation between the sex of the victim and the method of suicide used. (b) More women commit suicide than men. (c) Men display a greater tendency to use firearms to commit suicide than do women. (d) The correlation between method of suicide and sex of the victim is clearly positive. (e) Females prefer poison over any other method of committing suicide.


Answer

Relational Design - 100 Answer

The percent of cars listed in the table with 4-cylinder engines that are made in Germany is

(a) 10.5%.(b) 21%.(c) 50%.(d) 80%.(e) 91%.

Relational Design - 200 AnswerFrom the table we might conclude that

(a) there is clearly no relation between country of origin and # of cylinders. (b) the correlation between country of origin and # of cylinders is likely to be about 0.5. (c) a regression line fitted to these data would probably have a negative slope. (d) there is evidence of some relation between country of origin and number of cylinders. (e) the United States has far more cars than any of the other countries.

Control groups are used in experiments in order to

(a) control the effects of outside variables on the outcome.(b) control the subjects of a study to ensure that all participate equally.(c) guarantee that someone other than the investigators, who have a vested interest in the outcome, controls how the experiment is conducted.(d) achieve a proper and uniform level of randomization.(e) None of the above.


What electrical changes occur in muscles as they get tired? Student subjects hold their arms above their shoulders as long as they can. Meanwhile, the electrical activity in their arm muscles is measured. This is:(a) an observational study.(b) an uncontrolled experiment.(c) a randomized comparative experiment.(d) a matched pairs design.(e) impossible to describe unless more details of the study are provided.



The Community Intervention Trial for Smoking Cessation (COMMIT) asked whether a community-wide advertising campaign would reduce smoking. The researchers located 11 pairs of communities that were similar in location, size, economic status, and so on. One community in each pair participated in the advertising campaign and the other did not. This is(a) an observational study.(b) a matched pairs experiment.(c) a completely randomized experiment.(d) a block design.(e) impossible to answer unless more details of the study are provided.

Relational Design- 600 AnswerThe following two-way table categorizes suicides committed in a particular year by the sex of the victim and the method used.

Method Male FemaleFirearms 13,959 2,641Poison 3,148 2,469Hanging 3,222 709Other 1,457 690

Which of the following statements is consistent with the table? (a) There is absolutely no evidence of a relation between the sex of the victim and the method of suicide used. (b) More women commit suicide than men. (c) Men display a greater tendency to use firearms to commit suicide than do women. (d) The correlation between method of suicide and sex of the victim is clearly positive. (e) Females prefer poison over any other method of committing suicide.

Probability Sign. Tests - 100

Answer

A randomly selected student is asked to respond Yes, No, or Maybe to the question “Do you intend to vote in the next presidential election?” The sample space is { Yes, No, Maybe }. Which of the following represents a legitimate assignment of probabilities for this sample space?

(a) 0.4, 0.4, 0.2(b) 0.4, 0.6, 0.4(c) 0.3, 0.3, 0.3(d) 0.5, 0.3, –0.2(e) None of the above


Answer

If you choose a card at random from a well-shuffled deck of 52 cards, what is the probability that the card chosen is not a heart?

(a) 0.25 (b) 0.50(c) 0.75 (d) 1(e) None of the above


Answer

You play tennis regularly with a friend, and from past experience, you believe that the outcome of each match is independent. For any given match you have a probability of 0.6 of winning. The probability that you win the next two matches is

(a) 0.16. (b) 0.36. (c) 0.4. (d) 0.6.(e) 1.2.

Choose an American household at random and let X be the number of cars (including SUVs and light trucks) they own. Here is the probability model if we ignore the few households that own more than 5 cars: Number of cars X 0 1 2 3 4 5Probability 0.09 0.36 0.35 0.13 0.05 0.02 A housing company builds houses with two-car garages. What percent of households have more cars than the garage can hold? (a) 7% (b) 13% (c) 20% (d) 45%(e) 55%


Answer


Answer

Looking online (for example, at espn.go.com) you find the salaries of all 22 players for the Chicago Cubs as of opening day of the 2005 baseball season. The club total was $87 million, eighth in the major leagues. Which inference procedure would you use to estimate the average salary of the Cubs players?

(a)one-sample z interval for µ (b)one-sample t interval for µ(c)one-sample t test(d) one-sample z test(e) none of these


Answer

You read in the report of a psychology experiment that “separate analyses for our two groups of 12 participants revealed no overall placebo effect for our student group (mean = 0.08, SD = 0.37, t(11) = 0.49) and a significant effect for our non-student group (mean = 0.35, SD = 0.37, t(11) = 3.28, p < 0.01).” Are the two values given for the t test statistic correct? (The null hypothesis is that the mean effect is zero.) (a) Yes, both are correct.(b) The t statistic for the student group is correct, but the one for the non-student group is incorrect.(c) The t statistic for the non-student group is correct, but the one for the student group is incorrect.(d) Both t statistics are incorrect.(e) We can’t tell whether either t statistic is correct, because we aren’t given the actual data.

Probability Sign. Tests - 100 AnswerA randomly selected student is asked to respond Yes, No, or Maybe to the question “Do you intend to vote in the next presidential election?” The sample space is { Yes, No, Maybe }. Which of the following represents a legitimate assignment of probabilities for this sample space?

(a) 0.4, 0.4, 0.2(b) 0.4, 0.6, 0.4(c) 0.3, 0.3, 0.3(d) 0.5, 0.3, –0.2(e) None of the above

Probability Sign. Tests - 200 AnswerIf you choose a card at random from a well-shuffled deck of 52 cards, what is the probability that the card chosen is not a heart?

(a) 0.25 (b) 0.50(c) 0.75 (d) 1(e) None of the above

Probability Sign. Tests - 300 AnswerYou play tennis regularly with a friend, and from past experience, you believe that the outcome of each match is independent. For any given match you have a probability of 0.6 of winning. The probability that you win the next two matches is

(a) 0.16. (b) 0.36. (c) 0.4. (d) 0.6.(e) 1.2.

Choose an American household at random and let X be the number of cars (including SUVs and light trucks) they own. Here is the probability model if we ignore the few households that own more than 5 cars: Number of cars X 0 1 2 3 4 5Probability 0.09 0.36 0.35 0.13 0.05 0.02 A housing company builds houses with two-car garages. What percent of households have more cars than the garage can hold? (a) 7% (b) 13% (c) 20% (d) 45%(e) 55%

Probability Sign. Tests - 400 Answer

Looking online (for example, at espn.go.com) you find the salaries of all 22 players for the Chicago Cubs as of opening day of the 2005 baseball season. The club total was $87 million, eighth in the major leagues. Which inference procedure would you use to estimate the average salary of the Cubs players?

(a)one-sample z interval for µ (b)one-sample t interval for µ(c)one-sample t test(d) one-sample z test(e) none of these


You read in the report of a psychology experiment that “separate analyses for our two groups of 12 participants revealed no overall placebo effect for our student group (mean = 0.08, SD = 0.37, t(11) = 0.49) and a significant effect for our non-student group (mean = 0.35, SD = 0.37, t(11) = 3.28, p < 0.01).” Are the two values given for the t test statistic correct? (The null hypothesis is that the mean effect is zero.)

(a) Yes, both are correct.(b) The t statistic for the student group is

correct, but the one for the non-student group is incorrect.

(c)The t statistic for the non-student group is correct, but the one for the student group is incorrect.

(d) Both t statistics are incorrect.(e) We can’t tell whether either t statistic is

correct, because we aren’t given the actual data.


Sample Tests - 100

Answer

Following a dramatic drop of 500 points in the Dow Jones Industrial Average in September 1998, a poll conducted for the Associated Press found that 92% of those polled said that a year from now their family financial situation will be as good as it is today or better. The number 92% is a

(a) Statistic (b) Sample(c) Parameter (d) Population(e) None of the above.

Sample Tests - 200

Answer

In a large population, 46% of the households own VCRs. A simple random sample of 100 households is to be contacted and the sample proportion computed. The mean of the sampling distribution of the sample proportion is

(a) 46(b) 0.46(c) about 0.46, but not exactly 0.46(d) 0.00248(e) the answer cannot be computed from the information given.

Sample Tests - 300

Answer

If a statistic used to estimate a parameter is such that the mean of its sampling distribution is equal to the true value of the parameter being estimated, the statistic is said to be

(a) random (b) biased

(c) a proportion (d) unbiased(e) none of the above.

A simple random sample of 1000 Americans found that 61% were satisfied with the service provided by the dealer from which they bought their car. A simple random sample of 1000 Canadians found that 58% were satisfied with the service provided by the dealer from which they bought their car. The sampling variability associated with these statistics is:

(a) exactly the same. (b) smaller for the sample of Canadians because the

population of Canada is smaller than that of the United States, hence the sample is a larger

proportion of the population. (c) smaller for the sample of Canadians because the

percent satisfied was smaller than that for the Americans.

(d) larger for the Canadians because Canadian citizens are more widely dispersed throughout the country than in the United States, hence they have more variable views.

(e) about the same.

Sample Tests - 400 Answer

Sample Tests - 500The central limit theorem is important in statistics because it allows us to use the Normal distribution to make inferences concerning the population mean: (a) provided that the sample size is reasonably large (for any population). (b) provided that the population is Normally distributed and the sample size is reasonably large. (c) provided that the population is Normally distributed (for any sample size). (d) provided that the population is Normally distributed and the population variance is known (for any sample size). (e) provided that the population size is reasonably large (whether the population distribution is known or not).

Answer

Sample Tests - 600Which of the following is/are correct?I. The power of a significance test depends on the alternative value of the parameter.II. The probability of a Type II error is equal to the significance level of the test.III. Type I and Type II errors make sense only when a significance level has been chosen in advance.(a) I and II only(b) I and III only(c) II and III only(d) I, II, and III(e) None of the above gives the complete set of correct responses.

Answer

Sample Tests - 100 AnswerFollowing a dramatic drop of 500 points in the Dow Jones Industrial Average in September 1998, a poll conducted for the Associated Press found that 92% of those polled said that a year from now their family financial situation will be as good as it is today or better. The number 92% is a

(a) Statistic (b) Sample(c) Parameter (d) Population(e) None of the above.

In a large population, 46% of the households own VCRs. A simple random sample of 100 households is to be contacted and the sample proportion computed. The mean of the sampling distribution of the sample proportion is

(a) 46(b) 0.46(c) about 0.46, but not exactly 0.46(d) 0.00248(e) the answer cannot be computed from the information given.

Sample Tests - 200 Answer

Sample Tests - 300 AnswerIf a statistic used to estimate a parameter is such that the mean of its sampling distribution is equal to the true value of the parameter being estimated, the statistic is said to be

(a) random (b) biased

(c) a proportion (d) unbiased(e) none of the above.

A simple random sample of 1000 Americans found that 61% were satisfied with the service provided by the dealer from which they bought their car. A simple random sample of 1000 Canadians found that 58% were satisfied with the service provided by the dealer from which they bought their car. The sampling variability associated with these statistics is:

(a) exactly the same. (b) smaller for the sample of Canadians because the

population of Canada is smaller than that of the United States, hence the sample is a larger

proportion of the population. (c) smaller for the sample of Canadians because the

percent satisfied was smaller than that for the Americans.

(d) larger for the Canadians because Canadian citizens are more widely dispersed throughout the country than in the United States, hence they have more variable views.

(e) about the same.

Sample Tests-400 Answer

Sample Tests - 500 AnswerThe central limit theorem is important in statistics because it allows us to use the Normal distribution to make inferences concerning the population mean: (a) provided that the sample size is reasonably large (for any population). (b) provided that the population is Normally distributed and the sample size is reasonably large. (c) provided that the population is Normally distributed (for any sample size). (d) provided that the population is Normally distributed and the population variance is known (for any sample size). (e) provided that the population size is reasonably large (whether the population distribution is known or not).

Sample Tests - 600 AnswerWhich of the following is/are correct?I. The power of a significance test depends on the alternative value of the parameter.II. The probability of a Type II error is equal to the significance level of the test.III. Type I and Type II errors make sense only when a significance level has been chosen in advance.(a) I and II only(b) I and III only(c) II and III only(d) I, II, and III(e) None of the above gives the complete set of correct responses.

Anything Inferred - 100

A significance test allows you to reject a hypothesis in favor of an alternative Ha at the 5% level of significance. What can you say about significance at the 1% level?(a) can be rejected at the 1% level of significance.(b) There is insufficient evidence to reject at the 1% level of significance.(c) There is sufficient evidence to accept at the 1% level of significance.(d) Ha can be rejected at the 1% level of significance.(e) The answer can’t be determined from the information given.

Answer


Answer

An analyst, using a random sample of n = 500 families, obtained a 90% confidence interval for mean monthly family income for a large population: ($600, $800). If the analyst had used a 99% confidence level instead, the confidence interval would be:

(a) Narrower and would involve a larger risk of

being incorrect (b) Wider and would involve a smaller risk of

being incorrect (c) Narrower and would involve a smaller risk of

being incorrect (d) Wider and would involve a larger risk of

being incorrect (e) Wider but it cannot be determined whether

the risk of being incorrect would be larger or smaller


Answer

An opinion poll asks a random sample of adults whether they favor banning ownership of handguns by private citizens. A commentator believes that more than half of all adults favor such a ban. The null and alternative hypotheses you would use to test this claim are

(a)H0: p-hat = 0.5: Ha: p-hat > 0.5(b)H0: p-hat = 0.5: Ha: p-hat ≠ 0.5(c)H0: p = 0.5: Ha: p ≠ 0.5(d)H0: p = 0: Ha: p > 0 (e)None of the above

Anything Inferred - Anything Inferred - 400400

Answer

In preparing to use a t procedure, suppose we were not sure if the population was Normal. In which of the following circumstances would we not be safe using a t procedure?

(a) A stemplot of the data is roughly bell-shaped.(b) A histogram of the data shows moderate skewness.(c) A stemplot of the data has a large outlier.(d) The sample standard deviation is large.(e) The t procedures are robust, so it is always safe.


Answer

In an opinion poll, 25% of a random sample of 200 people said that they were strongly opposed to having a state lottery. The standard error of the sample proportion is approximately

(a) 0.03(b) 0.25(c) 0.0094(d) 6.12(e) 0.06(f) None of the above.


Answer

A 95% confidence interval for µ is calculated to be (1.7, 3.5). It is now decided to test the hypothesis H0: µ = 0 versus Ha: µ 0 at the = 0.05 level, using the same data as used to construct the confidence interval.

(a) We cannot test the hypothesis without the original data.

(b) We cannot test the hypothesis at the = 0.05 level since the = 0.05 test is connected to the 97.5% confidence interval.

(c) We can make the connection between hypothesis tests and confidence intervals only if the sample sizes are large.

(d) We would reject H0 at level = 0.05. (e) We would accept H0 at level = 0.05.

Anything Inferred - 100 Anything Inferred - 100 AnswerAnswer

A significance test allows you to reject a hypothesis in favor of an alternative Ha at the 5% level of significance. What can you say about significance at the 1% level?(a) can be rejected at the 1% level of significance.(b) There is insufficient evidence to reject at the 1% level of significance.(c) There is sufficient evidence to accept at the 1% level of significance.(d) Ha can be rejected at the 1% level of significance.(e) The answer can’t be determined from the information given.


An analyst, using a random sample of n = 500 families, obtained a 90% confidence interval for mean monthly family income for a large population: ($600, $800). If the analyst had used a 99% confidence level instead, the confidence interval would be:

(a) Narrower and would involve a larger risk of

being incorrect (b) Wider and would involve a smaller risk of

being incorrect (c) Narrower and would involve a smaller risk of

being incorrect (d) Wider and would involve a larger risk of

being incorrect (e) Wider but it cannot be determined whether

the risk of being incorrect would be larger or smaller

An opinion poll asks a random sample of adults whether they favor banning ownership of handguns by private citizens. A commentator believes that more than half of all adults favor such a ban. The null and alternative hypotheses you would use to test this claim are

(a)H0: p-hat = 0.5: Ha: p-hat > 0.5(b)H0: p-hat = 0.5: Ha: p-hat ≠ 0.5(c)H0: p = 0.5: Ha: p ≠ 0.5(d)H0: p = 0: Ha: p > 0 (e)None of the above



In preparing to use a t procedure, suppose we were not sure if the population was Normal. In which of the following circumstances would we not be safe using a t procedure?

(a) A stemplot of the data is roughly bell-shaped.

(b) A histogram of the data shows moderate skewness.

(c) A stemplot of the data has a large outlier.

(d) The sample standard deviation is large.

(e)The t procedures are robust, so it is always safe.


In an opinion poll, 25% of a random sample of 200 people said that they were strongly opposed to having a state lottery. The standard error of the sample proportion is approximately

(a) 0.03(b) 0.25(c) 0.0094(d) 6.12(e) 0.06(f) None of the above.


A 95% confidence interval for µ is calculated to be (1.7, 3.5). It is now decided to test the hypothesis H0: µ = 0 versus Ha: µ 0 at the = 0.05 level, using the same data as used to construct the confidence interval.

(a) We cannot test the hypothesis without the original data.

(b) We cannot test the hypothesis at the = 0.05 level since the = 0.05 test is connected to the 97.5% confidence interval.

(c) We can make the connection between hypothesis tests and confidence intervals only if the sample sizes are large.

(d) We would reject H0 at level = 0.05. (e) We would accept H0 at level = 0.05.

Final JeopardyFinal Jeopardy

A scientist is weighing each of 30 fish. She obtains a mean of 30 g and a standard deviation of 2 g. After completing the weighing, she finds that the scale was misaligned and always under reported every weight by 2 g that is, a fish that really weighed 26 g was reported to weigh 24 grams. What are the mean and standard deviation after correcting for the error in the scale?

(a)28 g, 2 g (b) 30 g, 4 g(c) 32 g, 2 g (d) 32 g, 4 g (e) 28

g, 4 g

100 200 300 400 biometric regression relational design probability signif. tests sample tests...

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