Question

A decision maker is interested in estimating the mean of a population based on a random sample. She wants the confidence level to be

90​%

and the margin of error to be ±0.50

She does not know what the population standard deviation​ is, so she has selected the pilot sample below. Based on this pilot​ sample, how many more items must be sampled so that the decision maker can make the desired confidence interval​ estimate?

8.50	4.87	10.95	15.05	14.78
16.95	1.27	9.06	14.36	5.64
7.28	3.25	2.63	6.07	6.92

The decision maker should sample ____ more items to make the desired confidence interval estimate.

Answer 1