Question

A sample of 40 people owned an average of 1.35 hats. It is known from a previous study that the population standard deviation of hat ownership is 0.63 hats. Construct a 95% confidence interval.

Answer 1

Answer:

(1,155, 1.545).

Step-by-step explanation:

From Normal distribution tables the z score for 95% CI  = 1.96.

Confidence Interval

= 1.35 +/- 1.96 * 0.63/√40

=  1.35 +/- 0.195

=  (1,155, 1.545).