
Arithmetic Mean 

Unit 8
> Lesson 2 of 8 
Problem: 
Scott took 7 math tests in one marking period. What is the mean test score?



89, 73, 84, 91, 87, 77, 94

Solution: 
The sum of these numbers is 595. Dividing the sum by the number of test scores we get:




Answer: 
The mean test score is 85.


Definition: 
The arithmetic mean of a set of data is found by taking
the sum of the data, and then dividing the sum by the total number of values in the set.
A mean is commonly referred to as an average. 
In the problem above, the mean was a whole number. This is not always the case. Let's look at
some more examples.
Example 1: 
Find the mean driving speed for 6 different cars on the same
highway.



66 mph, 57 mph, 71 mph, 54 mph, 69 mph, 58 mph

Solution: 
66 + 57 + 71 + 54 + 69 + 58 = 375



Answer: 
The mean driving speed is 62.5 mph.

Example 2: 
The Scheuern family drove through 4 midwestern states on their
summer vacation. Gasoline prices varied from state to state. What is the
mean gasoline price?



$1.79, $1.61, $1.96, $2.08


Solution: 
$1.79 + $1.61 + $1.96 + $2.08 = $7.44




Answer: 
The mean gasoline price is $1.86.

Example 3: 
A marathon race was completed by 5 participants in the times
given below. What is the mean race time for this marathon?



2.7 hr, 8.3 hr, 3.5 hr, 5.1 hr, 4.9 hr


Solution: 
2.7 + 8.3 + 3.5 + 5.1 + 4.9 = 24.5




Answer: 
The mean race time is 4.9 hr

Example 4: 
Find the mean swimming time rounded to the
nearest tenth:



2.6 min, 7.2 min, 3.5 min, 9.8 min, 2.5 min


Solution: 
2.6 + 7.2 + 3.5 + 9.8 + 2.5 = 25.6




Answer: 
The mean swimming time to the nearest tenth is 5.1 min.

Summary: 
The arithmetic mean of a set of n numbers is the sum of
the n numbers divided by n. The mean is commonly referred to as an average. 



Exercises
Directions: Find the mean of each set of data.
Click once in an ANSWER BOX and type in your answer; then click ENTER. After you click ENTER, a message will appear in the RESULTS BOX to
indicate whether your answer is correct or incorrect. To start over, click CLEAR. 
1.

Find the mean of the whole numbers listed below.
1, 8, 7, 6, 8, 3,
2, 5, 4, 5

2.

Find the mean of the decimals listed below.
5.3, 5.5, 2.2, 4.8, 3.2

3.

Find the mean rounded to the nearest tenth.
0.34, 0.12, 0.48, 0.56, 0.71, 0.8, 0.65, 0.82

4.

Employees at a retail store are paid the hourly wages listed
below. What is the mean hourly wage?
$7.50, $9.25, $8.75, $9.50, $7.25, $8.75

5.

What is the mean test score?
83, 71, 91, 79, 87, 80, 95, 79, 91, 85, 94,
73

This indepth lesson is by Gisele Glosser. You can find me on Google.
