Question

Fifty-nine items are randomly selected from a population of 650 items. The sample mean is 37, and the sample standard deviation 2. Develop a 90% confidence interval for the population mean. (Round the final answers to 2 decimal places.)            

    

The confidence interval is between       and

Answer 1

Solution :

Given that,

t /2,df = 1.672

Margin of error = E = t/2,df * (s /n)

= 1.672 * (2 / 59)

Margin of error = E = 0.44

The 90% confidence interval estimate of the population mean is,

- E < < + E

37 - 0.44 < < 37 + 0.44

36.56 < < 37.44

The confidence interval is between 36.56 and 37.44