Mean
Definition Of Mean
Mean of a set of numbers is the sum of the numbers divided by the number of items in the list. Mean of a set of n numbers a1, a2, a3, ..., an is given by 
More About Mean
Mean can also be called as average or arithmetic mean.
Examples of Mean
In order to find the mean of 4, 5, 6, 3, and 7, first we have to add the numbers and then divide the sum by the number of items.
4 + 5 + 6 + 3 + 7 = 25 i.e. the sum of the numbers is 25.
Mean = 
= 
= 
= 5
So, the mean of the data set 4, 5, 6, 3, and 7 is 5.
Video Examples: Basic Math : How to Work Out the Mean in Math
Solved Example on Mean
Ques: Find the mean weight of the data set shown. 5 lb, 48 lb, 31 lb, 31 lb, 41 lb, 20 lb, 19 lb, 5 lb
Choices:
A. 27 lb
B. 25 lb
C. 26 lb
D. 24 lb
Correct Answer: B
Solution:
Step 1: Mean weight = 
Step 2: Sum of the weights = 5 + 48 + 31 + 31 + 41 + 20 + 19 + 5
Step 3: = 200 lb [Add the weights.]
Step 4: Number of weights listed = 8
Step 5: Mean weight = 
= 25 lb [Substitute and simplify.]
Step 6: So, the mean weight of the data set is 25 lb.
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