1. Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes

2. Warm Up
Order the numbers from least to greatest.
1. 8, 6, 25, 7, 4, 12
2. 60, 11, 27, 45, 32
Divide
÷ ÷ 10
4, 6, 7, 8, 12, 25
11, 27, 32, 45, 60
180 76

3. Problem of the Day
Ms. Red, Ms. Blue, and Ms. Green attended a holiday party. They each wore a different- colored dress: red, blue, or green. Ms. Red said to the lady wearing the blue dress, “Did you notice that none of us is wearing a dress with the color that corresponds to our name?” Who wore which color dress?
Ms. Red: green; Ms. Blue: red; Ms. Green: blue

4. Learn to find the mean, median, mode and range of a data set.

5. Vocabulary
mean
median
mode
range

6. Players on a volleyball team measured how high they could jump
Players on a volleyball team measured how high they could jump. The results in inches are recorded in the table. 18 24 21 20 23 13
One way to describe this data set is to find the mean. The mean is the sum of all the items divided by the number of items in the set. Sometimes the mean is also called the average. The mean of this set of data is the average height that the vollyball team could jump.

7. Additional Example 1A: Finding the Mean of a Data Set
Find the mean of each data set. 1 2 4 5 3 8
Depths of Puddles (in.)‏
mean: = 28
28 ÷ 7 = 4
Add all values.
Divide the sum by the number of items.
The mean is 4 inches.

8. Number of Points Scored
Additional Example 1B: Finding the Mean of a Data Set
Find the mean of each data set. 7 84 75 96
Number of Points Scored
mean: = 262
262 ÷ 4 = 65.5
Add all values.
Divide the sum by the number of items.
The mean is 65.5 points. The average number of points scored is 65.5.

9. Rainfall per month (in.)‏
Check It Out: Example 1A
Find the mean of each data set. 9 6 5 2 10 1
Rainfall per month (in.)‏
mean: = 35
35 ÷ 7 = 5
Add all values.
Divide the sum by the number of items.
The mean is 5 inches.

10. Number of Points Scored
Check It Out: Example 1B
Find the mean of each data set. 12 47 26 53
Number of Points Scored
mean: = 138
138 ÷ 4 = 34.5
Add all values.
Divide the sum by the number of items.
The mean is 34.5 points. The average number of points scored is 34.5.

11. Some other descriptions of a set of data are called the median, mode, and range.
The median is the middle value when the data are in numerical order, or the mean of the two middle values if there are an even number of items.
The mode is the value or values that occur most often. There may be more than one mode for a data set. When all values occur an equal number of times, the data set has no mode.
The range is the difference between the least and greatest values in the set.

12. Additional Example 2: Finding the Mean, Median, Mode, and Range of a Data Set
Find the mean, median, mode, and range of the data set.
9th Grade
8th Grade
7th Grade
6th Grade
Car Wash Totals
mean: 4
= 13
Write the data in numerical order.
11, 12, 14, 15
median: 11, 12, 14, 15
There are an even number of items, so find the mean of the two middle values. 2
= 13
mode: none
range: 15 – 11 = 4
The mean is 13, the median is 13, there is no mode, and the range is 4.

13. Check It Out: Example 2
Find the mean, median, mode, and range of the data set.
9th Grade
8th Grade
7th Grade
6th Grade
Bake Sale Totals
mean: 4
= 16
Write the data in numerical order.
11, 14, 17, 22
median: 11, 14, 17, 22
There are an even number of items, so find the mean of the two middle values. 2
= 15.5
mode: none
range: 22 – 11 = 11
The mean is 16, the median is 15.5, there is no mode, and the range is 11.

14. Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems

15. Lesson Quiz
Use the following data set: , 20, 56, 47, 30, 18, 21.
1. Find the range. 2. Find the mean.
3. Find the median. 4. Find the mode.
5. Bonnie ran a mile in 8 minutes, 8 minutes, 7 minutes, 9 minutes, and 8 minutes. What was her mean time? 38 30 21 18
8 minutes

16. Lesson Quiz for Student Response Systems
1. Identify the range of the following data set.
20, 22, 58, 48, 32, 20, 23
A. 38
B. 28
C. 18
D. 8

17. Lesson Quiz for Student Response Systems
2. Identify the mean of the following data set.
20, 25, 60, 42, 30, 20, 20
A. 31
B. 34
C. 38
D. 42

18. Lesson Quiz for Student Response Systems
3. Identify the median of the following data set.
20, 22, 58, 48, 32, 20, 23
A. 48
B. 32
C. 23
D. 20

19. Lesson Quiz for Student Response Systems
4. Identify the mode of the following data set.
20, 28, 55, 48, 30, 20, 25
A. 20
B. 23
C. 25
D. 32

20. Lesson Quiz for Student Response Systems
5. Rebecca spent $7, $12, $8, and $13 over the past 4 days buying vegetables. What was the mean amount spent on vegetables?
A. $10
B. $9
C. $8
D. $7