Consider the data set.

1, 4, 5, 8, 9

(a) Find the range. (b) Use the defining formula to compute the sample standard deviation s. (c) Use the defining formula to compute the population standard deviation .

In order to use the defining formula for sample standard deviation, it is helpful to first calculate

(xx)²

for each data value in the data set

1,4,5,8,9.

Use the values in the data set and the previously determined mean,

x=5.4,

to complete the following table.

x	1	4	5	8	9
x	5.4	5.4	5.4	5.4	5.4
xx	4.4		0.4		3.6
(xx)2	19.36	1.96		6.76