1

Finding the Sample Mean

Given: The times, in seconds, required for a sample of students to perform a required task were:

6,

Find the sample mean x

10, 13, 11, 12, 8

2

The Formula - Knowing Its Parts

The calculation of a sample statistic requires the use of a formula. In this case, use:

(Do you have your sample data ready to use?)

x =xn

x is the “sum of x”, the sum of all data

• n is the “sample size”, the number of data

n

• x is “x-bar”, the sample mean

xx

3

60

First, find the numerator:

116 10 13 12 8

Finding the Numerator

Sample = { 6, 10, 13, 11, 12, 8 }

6 10 13 11 12 8+ + + + +==x =

nx

=x =nx

4

Finding the Denominator

Next, find the denominator:

Sample = { 6, 10, 13, 11, 12, 8 }1 2 3 4 5 6

6

n = 61 2 3 4 5 6

n =x =x 60

n =x =x 60

6

5

The Answer!

Lastly, divide and you have the answer!

=n

x =x 60

6= 10.0

The mean time is 10.0 seconds

=n

x =x 60

6