Arithmetic Mean

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

 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