7.U2.9-Measures of Center

• Mathematics

Unit 2: Lesson 8 

Measures of Central Tendency: Mean, Median, Mode 

At noon, the temperature was 12 degrees. It rose 8 degrees during the afternoon and then dropped 28 degrees by midnight. What was the temperature at midnight?

How do we describe a set of numbers?

Mathew's grades started out low, but he worked hard to raise them. His test scores are 23, 63, 68, 71, 95, 92, 95, 100, and 87.

How can he describe his grades to his parents? 

measures of central tendency

Measures of central tendency are ways to best represent the middle number of a set. 

Mean (Average)

Medium

Mode

What is the mean, medium and mode of Mathew's grades?

 23, 63, 68, 71, 95, 92, 95, 100, and 87

Find the mean for the numbers below
10 -1 -2 6 4

1. 4.6
2. 3.4
3. 4
4. -3.4

Find the outliers for the number set
6 3 -2 -18 10

1. -18
2. 10
3. -2
4. 3

Complete the following questions as a check-out. Find the median of the set by following the steps:
1. Put the numbers in order from left to right on number line
-15 -2 -1 -14 17 -9

1. -1,-2,-9,-14,-15,17
2. 17,-15,-14,-9,-2,-1
3. -15 -2 -1 -14 17 -9
4. -15,-14,-9,-2,-1,17

2. Find the 2 central numbers by crossing out the numbers on either side.

1. -1,-2
2. -14,-9
3. -9,-2
4. -1,-14

Find the average of the 2 middle number. This is the median.

1. -1.5
2. -11.5
3. -5.5
4. -7.5