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BUS/ST 350

Exam-Type Questions for TopicsIncluded on the Final Exam

Probability Basics, Probability Laws and Trees, Equally Likely Models

1) The employees of a company were surveyed on questions regarding their educational background (collegedegree or no college degree) and marital status (single or married). Of the 600 employees, 400 had collegedegrees, 100 were single, and 60 were single and had college degrees. The probability that an employee of thecompany is single OR has a college degree is:

A) 0.733 B) 0.25 C) 0.667 D) 0.10

Use the information in this paragraph to answer the first question below the table.Mothers Against Drunk Driving, a very visible group whose main focus is to educate the public about the harm caused bydrunk drivers, recently conducted a survey of traffic accidents. Four hundred accidents that occurred on a Saturday nightwere analyzed. Two items noted were the number of vehicles involved and whether alcohol played a role in the accident.The numbers are shown below:

Number of Vehicles InvolvedDid alcohol play a role? 1 2 3 Totals

Yes 50 100 20 170No 25 175 30 230

Totals 75 275 50 400

2) What is the probability that an accident involved alcohol OR a single vehicle?A) .0625 B) .6125 C) .4875 D) .1250

3) A witness to a hit-and-run accident told the police that the license number contained the letters R, L, and H insome order. The letters were followed by two digits. The witness cannot recall the two digits, but is certain thatthe two digits are different. How many license plate numbers will the police have to check?

A) 270 B) 540 C) 600 D) 300 E) 25

4) The horse show at the state fair consists of 25 entrants that compete for 1st, 2nd, and 3rd place. In how manyways can the judges choose 3 horses to rank 1st, 2nd, and 3rd? (Order makes a difference!)

A) 13,800 B) 25! × 3! C) 25!3!

D) 2,300 E) 25C3

5) For a sales promotion, the manufacturer places winning symbols under the caps of 10% of all Pepsi bottles. Youbuy a six-pack of Pepsi. What is the probability that you win something, that is, what is the probability that atleast one of the bottles has a winning symbol under the cap?

A) 0.531 B) 0.355 C) 0.469 D) 0.886 E) 0.114

6) According to a survey of American households, if annual household income is over $50,000, the probability thatthe residents own 2 cars is 80%. If annual household income is $50,000 or less, the probability that the residentsown 2 cars is 55%. Of the households surveyed, 60% had incomes over $50,000. The probability that theresidents of a household own 2 cars is: (use a probability tree)

A) 0.70 B) 0.48 C) 0.12 D) 0.22

1

BUS/ST 350 Final Exam-Type Questions

Random Variables, Probability Distributions, Expected Value, Standard Deviation, Algebra of ExpectedValue and Standard Deviation

7) The random variable X is the number of tennis balls ordered by customers at Tennis Online. Its probabilitydistribution is given in the table. Find E(X), the expected value of X.

x 3 6 9 12 15P(X = x) 0.14 0.22 0.36 0.18 0.10

A) 5.97 B) 8.88 C) 8.64 D) 9

8) The probability distribution for the number of heads in 4 tosses of a coin is given byNumber of

heads 0 1 2 3 4Probability 0.0625 0.25 0.375 0.25 .0625

The probability of at least one tail isA) 0.6875 B) 0.9375 C) 0.3125 D) 0.25 E) 0.75

9) The weight of medium size tomatoes selected at random from a bin at the local supermarket is a randomvariable X with expected value E(X) = 10 ounces and standard deviation SD(X) = 1 ounce. The weight of thetomatoes in pounds (1 pound = 16 ounces) is a random variable with standard deviation

A) 14

pound B) 1 pound C) 116

pound D) 256 pounds E) 16 pounds

10) In a certain game of chance at the state fair, your chances of winning are 0.2. If you win, you receive $3. If youlose, you must pay $1. If you play the game five times, your expected winnings are

A) $2 B) -$1 C) $3 D) $0 E) -$2

11) On a physical fitness test middle school boys are awarded one point for each push-up they can do, and a pointfor each sit-up. National results showed that boys average 18 pushups with a standard deviation of 4 push-ups,and 34 sit-ups with standard deviation 11. The mean of their combined (total) scores was therefore 18 + 34 = 52points. Assume that the number of push-ups and sit-ups by a middle school boy are independent. What is thestandard deviation of their combined scores?

A) 7.5 B) 11.7 C) 15 D) 5.3 E) 137

Probability Models: Binomial Geometric, Poisson

12) The Best Buy store at Crabtree Valley Mall has received a shipment of 1,500 CD's. The store manager will test25 CD's from the shipment; if 2 or more CD's are defective the store manager will reject the entire shipment. Ifin fact 1% of the CD's in the shipment are defective, what is the probability that the entire shipment is rejected?

A) 0.002 B) 0.026 C) 0.196 D) 0.222 E) 0.974

13) If n = 10 and p = 0.70, then the standard deviation of the binomial distribution is:A) 1.45 B) 7.00 C) 0.07 D) 2.1



14) A fair coin has come up “heads” 10 times in a row. The probability that the coin will come up heads on the nextflip is

A) It cannot be determined.B) 0.50.C) less than 0.50, since “tails” is due to come up.D) greater than 0.50, since it appears that we are in a streak of “heads.”

15) A friend plans to toss a fair coin 200 times. You watch the first 40 tosses, noticing that she got only 16 heads. Butthen you get bored and leave. If the coin is fair, how many heads do you expect her to have when she hasfinished the 200 tosses?

A) 100 B) 92 C) 80 D) 116 E) 96

16) A fair die is rolled 12 times. The number of times an even number occurs on the 12 rolls hasA) a binomial distribution with an expected value of 0.5.B) a binomial distribution with variance 3.C) a binomial distribution with a standard deviation of 3D) a binomial distribution with variance 32E) a binomial distribution with an expected value of 2.

17) BatCo, a company that sells batteries, claims that 99.5% of their batteries work. How many batteries would youexpect to buy, on average, until you find the first one that does not work?

A) 995 B) 200 C) 199 D) 994 E) 5

18) An ice cream stand reports that 12% of the cones they sell are “jumbo” size. You want to see what a“jumbo” cone looks like, so you stand and watch the sales for a while. What is the probability that the firstjumbo cone is the fourth cone you see them sell?

A) 0.08 B) 0.60 C) 0.93 D) 0.40 E) 0.33

19) If n = 10 and p = 0.70, then the standard deviation of the binomial distribution is:A) 0.07 B) 7.00 C) 2.1 D) 1.45

20) For quality control purposes, a company that manufactures sim chips for cell/smart phones routinely takessamples from its production process. Since it is important that these chips are nearly fault free, one inspectioncheck involves using microscopic equipment to count the number of imperfections on each chip. Suppose theaverage number of imperfections per 1000 sim chips is 3. What is the probability that a sample of 1000 sim chipshas 2 imperfections?

A) 0.2240 B) 0.2510 C) 0.4232 D) 0.1365 E) 0.4591

21) A fair die is rolled 12 times. The number of times an even number occurs on the 12 rolls hasA) a binomial distribution with a standard deviation of 3B) a binomial distribution with variance 3.C) a binomial distribution with an expected value of 2.D) a binomial distribution with an expected value of 0.5.E) a binomial distribution with variance 32

22) The mean number of errors per page made by a member of the word processing pool for a large company isthought to be 1.5 with the number of errors distributed according to a Poisson distribution. If three pages areexamined, what is the probability that more than 3 errors will be observed?

A) 0.6969 B) 0.6577 C) 0.7860 D) 0.7324



23) John Thurgood founded a company that translates Chinese books into English. His company is currently testinga computer-based translation service. Since Chinese symbols are difficult to translate, John assumes thecomputer program will make some errors, but then so do human translators. The computer error rate issupposed to be an average of 3 per 400 words of translation. Suppose John randomly selects a 1,200-wordpassage. Assuming that the Poisson distribution applies, if the computer error rate is actually 3 errors per 400words, find the probability that fewer than 9 errors will be found.

A) 0.000123 B) 0.4557 C) 0.0415 D) 0.0141

Sampling Distributions, Central Limit Theorem

Insurance company records indicate that 10% of its policyholders file claims involving theft or robbery of personal propertyfrom their homes. Suppose a random sample of 400 policyholders is selected.

24) The probability that the sample proportion of policyholders filing claims involving theft or robbery from theirhomes is less than 8% is

A) 0.7892 B) 0.1333 C) 0.0517 D) 0.0918 E) 0.4082

25) The Central Limit Theorem is important in statistics becauseA) for a large n, it says the sampling distribution of the sample mean is approximately normal, regardless of

the populationB) for any size sample, it says the sampling distribution of the sample mean is approximately normalC) for a large n, it says the population mean is approximately normalD) for any population, it says the sampling distribution of the sample mean is approximately normal,

regardless of the sample sizeE) For large sample size n the population mean is approximately normal regardless of the population.

26)^

In New York City 36% of adults in the city have credit card debts of more than $2000. A simple random sample

of n = 100 adults is obtained from New York City. Describe the sampling distribution of p, the sampleproportion of adults who have credit card debts of more than $2000.

A)^ ^

Approximately normal; E(p) = 0.36, SD(p) = 0.0023

B)^ ^

Binomial; E(p) = 36, SD(p) = 4.80

C)^ ^

Approximately normal; E(p) = 0.36, SD(p) = 0.048

D)^ ^

Approximately normal; E(p) = 36, SD(p) = 4.8

27) The owner of a computer repair shop has determined that their daily revenue has mean $7200 and standarddeviation $1200. The daily revenue totals for the next 30 days will be monitored. What is the probability thatthe mean daily revenue for the next 30 days will exceed $7500?

A) 0.9147 B) 0.0869 C) 0.0853 D) 0.9131

Confidence Intervals for an Unknown Population Proportion p; Required Sample Size to Estimate p

28) A university dean is interested in determining the proportion of students who receive some sort of financial aid.Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 ofthem are receiving financial aid. Use a 99% confidence interval to estimate the true proportion of students onfinancial aid.

A) 0.59 ± 0.003 B) 0.59 ± 0.090 C) 0.59 ± 0.007 D) 0.59 ± 0.623



29) We have calculated a confidence interval based on a sample of size n = 100. Now we want a new interval withthe same level of condfidence but with a margin of error that is only one-fourth as large. How large does ournew sample need to be?

A) 400 B) 50 C) 1600 D) 200 E) 25

30) What type of car is more popular among college students, American or foreign? One hundred fifty-nine collegestudents were randomly sampled and each was asked which type of car he or she prefers.. The resulting 90%confidence interval for the proportion p of college students that prefer American cars is (0.332, 0.460). Which ofthe following is a correct interpretation of the interval?

A) We are 90% confident that the interval (0.332, 0.460) contains the true proportion p of all college studentswho prefer American cars.

B) 90% of all college students prefer American cars between .332 and .460 of the time.C) We are 90% confident that the sample proportion of the 159 sampled students who prefer American cars

falls between .332 and .460.D) Between 0.332 and 0.446 of American cars are preferred by college students.E) We are 90% confident that the proportion p of all college students who prefer American cars falls between

.332 and .460.

31) In a college student poll, it is of interest to estimate the proportion p of students in favor of changing from aquarter-system to a semester-system. How many students should be polled so that we can estimate p to within0.09 using a 99% confidence interval? No information is available concerning an approximate value of p.

A) 114 B) 182 C) 206 D) 261

32) Five years ago at a large university the proportion of business majors that were female was 0.54. Using theinformation in the previous sentence, what total size sample would be necessary if we wanted to estimate thecurrent true proportion to within ±0.08 using 95% confidence?

A) 597 B) 105 C) 150 D) 420

Hypothesis Tests for a Population Proportion p

33) A P-value indicatesA) the probability of obtaining a value of the test statistic as extreme or more extreme than what we obtained,

given that the null hypothesis is true.B) the probability of obtaining a value of the test statistic as extreme or more extreme than what we obtained,

given that the alternative hypothesis is trueC) the probability that the alternative hypothesis is true.D) the probability that the null hypothesis is true.E) The probability that we have made a mistake.

34) A medical school claims that more than 28% of its students plan to go into general practice. It is found thatamong a random sample of 130 of the school's students, 32.3% of them plan to go into general practice. Theapproximate P-value for the test H0: p = 0.28, Ha: p > 0.28 of the school's claim is

A) 0.8630 B) 0.3078 C) 0.1370 D) 0.1469



35) A truck company wants on-time delivery for 98% of the parts they order from a metal manufacturing plant.They have been ordering from Hudson Manufacturing but will switch to a new, cheaper manufacturer(Steel-R-Us) unless there is evidence that this new manufacturer cannot meet the 98% on-time goal. As a testthe truck company purchases a random sample of metal parts from Steel-R-Us, and then determines if theseparts were delivered on-time. Which hypotheses should they test?

A)^

^H0: p = 0.98

HA: p < 0.98

B) H0: p > 0.98HA: p = 0.9

C) H0: p = 0.98HA: p < 0.98

D)^

^H0: p = 0.98

HA: p > 0.98

E) H0: p = 0.98HA: p > 0.98

Confidence Intervals for an Unknown Population Mean ; Required Sample Size to Estimate

36) Top management at a large software company wishes to estimate the average number of hours its firm'sprofessional employees volunteer in the local community. Based on past similar studies, the standard deviationwas found to be 2.22 hours. If top management wants to estimate the average number of hours volunteered permonth by their professional staff to within one hour with 99% confidence, how many randomly selectedprofessional employees would they need to sample?

A) 44 B) 33 C) 25 D) 19 E) 54

37) A popular restaurant takes a random sample n = 25 customers and records how long each occupied a table.They found a sample mean of 1.2 hours and a sample standard deviation of 0.3 hours. Find the 95 percentconfidence interval for the mean.

A) 1.2 ± .609 B) 1.2 ± .118 C) 1.2 ± .588 D) 1.2 ± .124

38) A manufacturer of cheese filled ravioli supplies a pizza restaurant chain. Based on data collected from itsautomatic filling process, the amount of cheese inserted into the ravioli is normally distributed. To make surethat the automatic filling process is on target, quality control inspectors take a sample of 25 ravioli and measurethe weight of cheese filling. They find a sample mean weight of 15 grams with a standard deviation of 1.5grams. What is the margin of error at 90% confidence?

A) 0.5133 grams B) 0.8391 grams C) 0.3 grams D) 1.5 grams E) 0.06 grams

Hypothesis Tests for a Population Mean

39) Insurance companies track life expectancy information to assist in determining the cost of life insurance policies.Last year the average life expectancy of all policyholders was 77 years. ABI Insurance wants to determine iftheir clients now have a longer life expectancy, on average, so they randomly sample 20 of their recently paidpolicies. The sample has a mean of 78.6 years and a standard deviation of 4.48 years. The P-value associatedwith the resulting test statistic is 0.063. Which of the following is the correct conclusion?

I. We fail to reject the null hypothesis.II. We reject the null hypothesis.III. There is not significant evidence to indicate an increase in average life expectancy.

A) III onlyB) I and III onlyC) II and III onlyD) I onlyE) II only



40) Suppose we want to test H0 : µ = 30 versus HA : µ < 30. Which of the following possible sample results basedon a sample of size 36 gives the strongest evidence to reject H0 in favor of HA?

A) X = 26, s = 9 B) X = 28, s = 6 C) X = 27, s = 4 D) X = 32, s = 2

41) A major airline is concerned that the waiting time for customers at its ticket counter may be exceeding its targetaverage of 190 seconds. To test this, the company has selected a random sample of 100 customers and timesthem from when the customer first arrives at the checkout line until he or she is at the counter being served bythe ticket agent. The mean time for this sample was 202 seconds with a standard deviation of 28 seconds. Whatis the correct formula for the calculation of the test statistic for this hypothesis test?

A) t = 190-20228

B) t = 202-19028

C) t = 190-20228/ 100

D) t = 202-19028/ 100

. E) t = 202-19028 100

Confidence Intervals for the Difference p1-p2 Between Two Unknown Population Proportions

42) A relief fund is set up to collect donations for the families affected by recent storms. A random sample of 400people shows that 28% of those 200 who were contacted by telephone actually made contributions compared toonly 18% of the 200 who received first class mail requests. Which formula calculates the 95% confidence intervalfor the difference in the proportions of people who make donations if contacted by telephone or first class mail?

A) (0.28 - 0.18) ± 1.96 (0.23)(0.77)200

B) (0.28 - 0.18) ± 1.96 (0.23)(0.77)200

+(0.23)(0.77)

200

C) (0.28 - 0.18) ± 1.96 (0.23)(0.77)400

D) (0.28 - 0.18) ± 1.96 (0.28)(0.72)400

+(0.18)(0.82)

400

E) (0.28 - 0.18) ± 1.96 (0.28)(0.72)200

+(0.18)(0.82)

200

43) In a recent survey of drinking laws, a random sample of 1000 women showed that 65% were in favor ofincreasing the legal drinking age. In a random sample of 1000 men, 60% favored increasing the legal drinkingage. Construct a 95% confidence interval for p1 - p2.

A) (0.008, 0.092) B) (0.587, 0.912) C) (-2.153, 1.679) D) (-1.423, 1.432)



44) Assume the proportion of students retained at a certain university in 2008 is p08 and the proportion of studentsretained in 2009 is p09. Based on a recent study, a 90% confidence interval for p08 - p09 is (-0.0398, 0.0262).Give an interpretation of this confidence interval.

A) We are 90% confident that the proportion of students retained in 2009 is between 3.98% less and 2.62%more than the proportion of students retained in 2008.

B) There is a 90% probability that the proportion of students retained in 2009 is between 3.98% less and 2.62%more than the proportion of students retained in 2008.

C) There is a 90% probability that the proportion of students retained in 2008 is between 3.98% less and 2.62%more than the proportion of students retained in 2009.

D) We are 90% confident that the proportion of students retained in 2008 is between 3.98% less and 2.62%more than the proportion of students retained in 2009.

E) If samples were repeatedly drawn from the same populations under the same circumstances, the truepopulation difference (p08 –p09) would be between -0.0398 and 0.0262 90% of the time.

Confidence Intervals for the Difference 1- 2 Between Two Unknown Population Means

45) Education and child psychology experts claim that the medication given to children diagnosed with AttentionDeficit Hyperactivity Disorder (ADHD) improves academic performance. But many parent organizations,worried about giving young children drugs that can have adverse side-effects, claim that teachers showfavoritism toward ADHD children who take medication over ADHD children who do not take medication. Toinvestigate this claim the teachers of 75 ADHD children were told that the children were receiving medication,but the children were actually given a sugar pill. The same teachers were told that 50 different ADHD childrenwere not taking any medication. Grades given to the ADHD students taking sugar pills had mean 85 andstandard deviation 7; grades given to the ADHD children not taking any medication had mean 79 and standarddeviation 5. A 99% confidence interval for the difference in mean grades between ADHD students taking sugarpills and ADHD students not taking any medication is: (use minimum (n1-1, n2-1) to estimate the degrees offreedom ).

A) (85-79) ± 2.6800 7275

+5250

B) (85-79) ± 2.0096 7275

+5250

C) (85-79) ± 2.0096 775

+550

D) (85-79) ± 2.6800 7275

+5250

E) (85-79) ± 2.6800 775

+550



46) A grocery store is interested in determining whether or not a difference exists between the shelf life of Hot'nNow doughnuts and Sugar Yum doughnuts. A random sample of 100 boxes of each brand was selected and themean shelf life in days was determined for each brand. A 90% confidence interval for the difference of themeans, µHN - µSY, was determined to be (1.1, 2.4).

A) Since the values in the confidence interval are positive, the probability that the mean shelf life of Hot'nNow doughnuts is longer than the mean shelf life of Sugar Yum doughnuts is 90%.

B) We are 90% confident that the interval (1.1, 2.4) captures the number of days that the mean shelf life ofHot'n Now doughnuts exceeds the mean shelf life of Sugar Yum doughnuts.

C) There is a 90% chance that a randomly selected box of Hot'n Now doughnuts will have a shelf life that isbetween 1.1 and 2.4 days longer than a randomly selected box of Sugar Yum doughnuts.

D) Since the values in the confidence interval are positive, the probability that the mean shelf life of SugarYum doughnuts is longer than the mean shelf life of Hot'n Now doughnuts is 90%.

E) We are 90% confident that the interval (1.1, 2.4) captures the number of days that the mean shelf life ofSugar Yum doughnuts exceeds the mean shelf life of Hot'n Now doughnuts.

47) A major retail clothing store is interested in estimating the difference in mean monthly purchases by customerswho use the store's in-house credit card versus using a Visa, Mastercard, or one of the other major credit cards.To do this, they have randomly selected a sample of customers who have made one or more purchases witheach of the types of credit cards. The following represents the results of the sampling:

In-House Credit Card National Credit CardSample Size: 86 113Mean Monthly Purchases: $45.67 $39.87Standard Deviation: $10.90 $12.47

Based on these sample data, what is the lower bound for the 95 percent confidence interval for the differencebetween population means? (Use min(n1-1, n2-1) for the degrees of freedom)

A) Approximately $2.58 B) Approximately $3.41C) About $5.28 D) Approximately $4.85

Inference in Simple Linear Regression

48)

^

The data below are the final exam scores of 10 randomly selected students from a statistics class and the numberof hours they slept the night before the exam. Construct a 95% confidence interval for the mean final exam score

for all students that got x = 7 hours of sleep the night before the exam, given that y = 5.044x + 56.11, x = 4.2,sx=1.874, and se = 6.305.

Hours, xScores, y

3 65

5 80

2 60

8 88

2 66

4 78

4 85

5 90

6 90

3 71

A) (74.54, 108.30) B) (82.840, 99.996) C) (79.16, 112.34) D) (77.21, 110.45)

49)

^

The data below are the final exam scores of 10 randomly selected students from a statistics class and the numberof hours they slept the night before the exam. Construct a 95% prediction interval for the final exam score for an

individual student who slept x = 7 hours the night before the exam, given that y = 5.044x + 56.11 and se = 6.305.Hours, xScores, y

3 65

5 80

2 60

8 88

2 66

4 78

4 85

5 90

6 90

3 71

A) (55.43, 78.19) B) (74.54, 108.30) C) (77.21, 110.45) D) (82.840, 99.996)



50) The number of hours of training time received by employees and the time it took (in minutes) for them totrouble shoot their last process problem was estimated using a regression equation. The 95% prediction intervalfor trouble shooting time with 8 hours of training was determined to be 12.822 to 19.261. The correctinterpretation is

A) The troubleshooting time by a line worker who received 8 hours of training will be between 12.822 and19.261 minutes 95% of the time.

B) We can be 95% confident that the trouble shooting time by a particular line worker who received 8 hoursof training will be between 12.822 and 19.261 minutes.

C) We can be 95% confident that troubleshooting times will be between 12.822 and 19.261 minutes.D) We can be 95% confident that the average trouble shooting time by line workers receiving 8 hours of

training is between 12.822 and 19.261 minutes.E) 95% of the time the average troubleshooting time is between 12.822 and 19.261 minutes.

51) As the carbon content in steel increases, its ductility tends to decrease. A researcher at a steel companymeasures carbon content and ductility for a sample of 15 types of steel. Use the following regression results tofind the 95% confidence interval for the slope of the regression equation.

Predictor Coef SE Coef T PConstant 7.671 1.507 5.09 0.000Carbon Content -3.296 1.097 -3.01 0.010

A) 6.164 to 9.178B) -5.456 to -1.136C) 2.581 to 12.761D) -4.393 to -2.199E) -5.666 to -0.926

52) According to the partial regression analysis output below, what is the t-statistic to test whether the regressionslope is significant?

Regression Analysis: Tourism ($ bill) versus Visitors (mill)The regression equation is: Tourism ($ bill) = 21.5 + 0.295 Visitors (mill)

Predictor Coef SE CoefConstant 21.464 3.462Visitors (mill) 0.29497 0.07917

S = 2.58307 R-Sq = 63.4%

A) 2.58307 B) 0.07917 C) 6.20 D) 3.73 E) 13.88

53) Data for the one-way commute times x (in minutes) and the number of class absences y they had werecollected for 9 selected students in a summer class. Find the standard error of estimate, se, given the followingsummary statistics:

9

i=1y 2

i = 813, 9

i=1xi = 779,

9

i=1yi = 77, b1= 0.4485,

9

i=1xi yi = 6995

A) 0.934 B) 1.007 C) 0.815 D) 1.162



54) A sales manager claims that there is a relationship between college GPA and sales performance (number ofunits sold) among salespeople hired within the last year. Use the regression results shown below to test herclaim.

Predictor Coef SE Coef T PConstant -0.484 3.256 -0.15 0.884GPA 7.423 1.044 7.11 0.000

A) None of theseB) fail to reject the null hypothesis and conclude that there is a significant relationship between GPA and

sales performanceC) fail to reject the null hypothesis and conclude that there is no significant relationship between GPA and

sales performanceD) reject the null hypothesis and conclude that there is no significant relationship between GPA and sales

performanceE) reject the null hypothesis and conclude that there is a significant relationship between GPA and sales

performance

Multiple Regression, Dummy Variables, Interaction Terms

55)

^

The regression equation that relates a student's weight to the number of hours spent on the computer, x1, thenumber of hours viewing television, x2, and the number of hours on their cell phone, x3, per day is

y = 125.5 + 3.26x1 + 4.27x2 + 1.75x3. What is a student's expected weight change if the amount of television isincreased by 1 hour, with the number of hours on the computer and talking on their cell phone held constant?

A) 3.26 pounds B) 125.5 pounds C) 1.75 pounds D) 4.27 pounds

56) In a multiple regression model, industry (1=high tech, 0=financial services), job growth, number of employees,and innovative index were used to predict turnover rate in a sample of firms. The coefficient of Industry is-2.8329. This means that for firms with the same innovative index score, job growth and number of employeesthe turnover rate will, on average, be

A) 2.83% less for a firm from the financial services compared to the high tech industryB) 2.83% more for a firm from the high tech industry compared to the financial servicesC) 0.47% less for a firm from the financial services compared to the high tech industryD) 2.83% less for a firm from high tech industry compared to financial servicesE) 6.03% less for a firm from the high tech industry compared to the financial services



57) A multiple regression is shown for a data set of yachts where the dependent variable is the price in thousands ofdollars.

Given this information, which of the following is true regarding the slope coefficient for Age, where Agerepresents how many years old the yacht is?

A) On average the price of the yacht falls by $1778 per yearB) On average the yacht is 1.778 years older per $1000 price changeC) On average the price of the yacht increases by $1778 per yearD) On average the price of the yacht falls by $1.778 per year

58) An elections officer wants to model voter turnout C in a precinct as a function of the type of precinct: urban,suburban, or rural. The elections officer uses the following regression model:y = 0 + 1x1 + 2x2 + wherex1 = 1 if urban, 0 if not,x2 = 1 if suburban, 0 if not.

Inte rpre t the va lue of 2.A) the diffe rence be tween the mean voter turnout for suburban and rura l precinctsB) the ra te of incre ase in voter turnout y for s uburban precinctsC) the mean vote r turnout for suburban precinctsD) the diffe rence be tween the mean voter turnout for suburban and urban precincts



59) The editors of a national automotive magazine recently studied 30 different automobiles sold in the UnitedStates with the intent of seeing whether they could develop a multiple regression model to explain the variationin highway miles per gallon. A number of different independent variables were collected. The followingregression output (with some values missing) was recently presented to the editors by the magazine's analysts:

Based on this output and your understanding of multiple regression analysis, what percentage of variation inthe dependent variable is explained by the regression model?

A) approximately 37%B) over 90 %C) approximately 82%D) approximately 89.9%E) approximately 95%



60) What does the scatterplot below suggest about developing a multiple regression model to predict turnover rateusing job growth and industry as predictor variables?

A) Using the interaction term Job Growth*Industry in the model is appropriate.B) Job Growth should not be included in the model as a variable.C) Using Job Growth as an indicator variable in this model is appropriate.D) None of these.E) Using Industry as an indicator variable in this model is appropriate.


Answer KeyTestname: EXAM TYPE QUESTIONS FINAL EXAM 350

1) A2) C3) B4) A5) C6) A7) C8) B9) C

10) B11) B12) B13) A14) B15) E16) B17) B18) A19) D20) A21) B22) B23) B24) D25) A26) C27) C28) B29) C30) A31) C32) C33) A34) C35) C36) B37) D38) A39) B40) C41) D42) E43) A44) D45) D46) B47) A48) B49) B50) B


Answer KeyTestname: EXAM TYPE QUESTIONS FINAL EXAM 350

51) E52) D53) A54) E55) D56) D57) A58) A59) C60) E


bus/st 350 exam type questions for topics included on the ...reiland/courses/st350...10) in a...

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