The grade point averages(GPA) for 12

12 randomly selected college students are shown on the right. Complete parts(a) through(c) below.

Assume the population is normally distributed.

2.2

2.2

3.3

3.3

2.8

2.8

1.8

1.8

0.9

0.9

4.0

4.0

2.2

2.2

1.5

1.5

3.6

3.6

0.3

0.3

2.4

2.4

3.4

3.4

(a) Find the sample mean.

x overbar

xequals

=

nothing

(Round to two decimal places asneeded.)

(b) Find the sample standard deviation.

sequals

=

nothing

(Round to two decimal places asneeded.)

(c) Construct a 95

95% confidence interval for the population mean mu

.

A 95

95% confidence interval for the population mean is left parenthesis nothing comma nothing right parenthesis .

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