Question

Suppose an Umoja Program Coordinator at another college follows your lead and decides to collect the same type of data on their campus. The following data represents the number of learning communities attended for a random sample of 20 Umoja students at East College.

8	9	13	4	7	5	1	14	9	13
6	16	6	16	18	3	5	10	2	14

Use this information to answer questions #4 through #5.

Question 4

What is the sample mean? (round to the thousandths if necessary)

Question 5

What is the standard deviation? (round to the thousandths if necessary)

Answer 1

Solution:

We are given a sample of size n = 20

Q. 4

Sample mean = (Sum of observations)/(number of observations)

= (8 + 9 + 13 + 4 + ...........+ 2 + 14)/20

= 8.950

Sample mean = 8.950

Q. 5

	x	x2
	8	64
	9	81
	13	169
	4	16
	7	49
	5	25
	1	1
	14	196
	9	81
	13	169
	6	36
	16	256
	6	36
	16	256
	18	324
	3	9
	5	25
	10	100
	2	4
	14	196
Sum	179	2093

Sample variance s² =

= [1/(20 - 1)]* [2093 - (179²/20) ]

= 25.8394736842

Now ,

standard deviation s = variance = 25.8394736842= 5.083

standard deviation = 5.083