Dr. Fowler CCM1A

EXAM REVIEW 02

Categorical Variable

A variable is categorical if each observation belongs to categories.

Examples:1. Gender (Male or Female)2. Religion (Christian, Catholic,

Jewish, …)3. Type of residence (Apt, Condo, …)4. Belief in life after death (Yes or

No)5. Hair color.

Quantitative Variable

A variable is called quantitative if observations take numerical values or “quantities”.

Examples:1. Age2. Number of siblings3. Annual Income4. Number of minutes

Histograms

1) What would be the most appropriate scale to use when creating a histogram for the salaries of Nurses at a Hospital? The salaries range from $20,000 to $50,000.

A. $10 incrementsB. $100 incrementsC. $1,000 incrementsD. $5,000 increments

Graph that uses bars to portray frequencies for a quantitative variable.

ANSWER = D

Original inequality

Add c to each side.Simplify.Subtract 6 from each side.Simplify.

Divide each side by 4.

Simplify.

Combine like terms.Distributive Property

Distributive Property

Given two points on a line, find the slope:

4. (5, 2), (1, 0)

5. (3, -3), (3, -1)

6. (-4, -2), (4, -2)

12

12

xx

yy

run

rise

51

20

4

2

33

31

44

22

0

2

33

31 UndefinedNO slope

44

220

8

0

X1y1 X2

y2

2

1

y = mx + b.

m = slopem = rate of change

b = y-intercept

Given an equation of a line, find theslope and y-intercept.

Example: Which has the Biggest rate of change?:

A) y = 3x + ½ B) y = x + 1000

Answer:A) 3 is bigger than 1

Copyright © 2000 by Monica Yuskaitis

Definition

•MeanMean – the average of a group of numbers.

2, 5, 2, 1, 5Mean = 3Mean = 3

Copyright © 2000 by Monica Yuskaitis

Definition•MedianMedian – the middle number in a set of ordered numbers.

1, 3, 7, 10, 13Median = 7Median = 7

Copyright © 2000 by Monica Yuskaitis

Definition•ModeMode – the number that appears most frequently in a set of numbers.

1, 1, 3, 7, 10, 13Mode = 1Mode = 1

Copyright © 2000 by Monica Yuskaitis

Definition•RangeRange – the difference

between the greatest and the least value in a set of numbers.

1, 1, 3, 7, 10, 13Range = 12Range = 12

Example 1 – You are given a set of numbers

Find the 5 Number Summary:

Step 1 - Order the set of numbers from least to greatest (very important)

2. Find the median. The median is the middle number. If the data has two middle numbers, find the mean of the two numbers. What is the median?

Step 2 – Find the Median

3. Find the lower and upper medians or quartiles. These are the middle numbers on each side of the median. What are they?

Step 3 – Upper & Lower Quartiles

Now you are ready to construct the actual box & whisker graph. First you will need to draw an ordinary number line that extends far enough in both directions to include all the numbers in your data:

Step 4 – Draw a Number Line

Locate the main median 12 using a vertical line just above your number line:

Step 5 – Draw the Parts

Locate the lower median 8.5 and the upper median 14 with similar vertical lines:

Step 5 – Draw the Parts

Next, draw a box using the lower and upper median lines as endpoints:

Step 5 – Draw the Parts

Finally, the whiskers extend out to the data's smallest number 5 and largest number 20:

Step 5 – Draw the Parts

Step 6 - Label the Parts of a Box-and-Whisker Plot

1 23

54

Name the parts of a Box-and-Whisker Plot

Median Upper QuartileLower Quartile

Lower Extreme Upper Extreme

1) Solve 5m - 8 > 12

+ 8 + 8

5m > 20

5 5

m > 4

5(4) – 8 = 12

1. Draw “the river” 2. Add 8 to both sides3. Simplify4. Divide both sides by 55. Simplify6. Check your answer7. Graph the solution

o4 53

Excellent Job !!!Well Done

Stop NotesWork on Review