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Dr. Fowler  CCM1A
EXAM REVIEW 02
Categorical Variable
A variable is categorical if each
observation belongs to categories.
 Examples:
1.
2.
3.
4.
5.
Gender (Male or Female)
Religion (Christian, Catholic, Jewish, …)
Type of residence (Apt, Condo, …)
Belief in life after death (Yes or No)
Hair color.
Quantitative Variable
A variable is called quantitative if observations take
numerical values or “quantities”.

Examples:
1.
2.
3.
4.
Age
Number of siblings
Annual Income
Number of minutes
Histograms
Graph that uses bars to portray
frequencies for a quantitative variable.

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 increments
B. $100 increments
C. $1,000 increments
ANSWER = D
D. $5,000 increments
Distributive Property
Original inequality
Distributive Property
Combine like terms.
Add c to each side.
Simplify.
Subtract 6 from each side.
Simplify.
Divide each side by 4.
Simplify.
Given two points on a line, find the slope:
4. (5, 2), (1, 0)
X1 y1
rise y 2  y1

run x 2  x1
02 2 1


1 5  4 2
X2 y2
5. (3, -3), (3, -1)
6. (-4, -2), (4, -2)
 1  3

33
1  3 2
 
33 0
 2  2

4  4
22

44
Undefined
NO slope
0
0
8
Given an equation of a line, find the
slope and y-intercept.
y = mx + b.
m = slope
m = rate of change
b = 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
Definition
• Mean – the average of a
group of numbers.
2, 5, 2, 1, 5
Mean = 3
Copyright © 2000 by Monica Yuskaitis
Definition
• Median – the middle number
in a set of ordered numbers.
1, 3, 7, 10, 13
Median = 7
Copyright © 2000 by Monica Yuskaitis
Definition
• Mode – the number that
appears most frequently in a
set of numbers.
1, 1, 3, 7, 10, 13
Mode = 1
Copyright © 2000 by Monica Yuskaitis
Definition
• Range – the difference between
the greatest and the least value
in a set of numbers.
1, 1, 3, 7, 10, 13
Range = 12
Copyright © 2000 by Monica Yuskaitis
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)
Step 2 – Find the Median
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 3 – Upper & Lower Quartiles
3. Find the lower and upper
medians or quartiles. These are
the middle numbers on each side
of the median. What are they?
Step 4 – Draw a Number Line
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 5 – Draw the Parts
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 6 - Label the Parts of
a Box-and-Whisker Plot
Lower Quartile Median Upper Quartile
Upper Extreme
Lower Extreme
3
1
2
4
5
Name the parts of a Box-and-Whisker Plot
1.
2.
3.
4.
5.
6.
7.
1) Solve 5m - 8 > 12
Draw “the river”
+8 +8
Add 8 to both sides
5m
> 20
Simplify
Divide both sides by 5
5
5
Simplify
Check your answer
m>4
Graph the solution
5(4) – 8 = 12
3
o
4
5
Excellent Job !!!
Well Done
Stop Notes
Work on Review