# Sample Mean

## Online Tutoring Is The Easiest, Most Cost-Effective Way For Students To Get The Help They Need Whenever They Need It.

#### SIGN UP FOR A FREE TRIAL

Definition: -The sample mean is the average of a group of numbers and is computes by summing all the numbers and dividing by the numbers. Because the sample mean is so widely used, most statisticians refer to it simply as the mean or average.

The sample mean is represented by x?. The formula for computing the sample mean is given as follows

Sample mean = Sum of all values/ Number of sample.
x? = ∑x / n                                                                   Where.∑x= Sum of all values
n = Number of sample

Example: - Last year’s incomes of five randomly selected families were
36,150            95,750            54,985            77,490            23,740

Find the sample mean.

Solution: -The sample mean formula is

Sample mean = Sum of all values/ Number of sample.
x? = ∑x / n

=(36150+95750+54985+77490+23740)/ 5       Since there are five sample
So n= 5
=288115/5
=57623

Therefore sample mean of this data set= 57,623

Other example: - The age of 10 randomly selected students from a class are
21        19        27        22        29        19        25        21        22        30

Find the sample mean.

The sample mean formula is

Sample mean = Sum of all values/ Number of sample.
x? = ∑x / n

=(21+19+27+22+29+19+25+21+22+30)/10      Since there are ten sample
So n= 10
= 235/ 10
=23.5

Therefore sample mean of this data set= 23.5