Question

You measure 32 textbooks' weights, and find they have a mean weight of 79 ounces. Assume the population standard deviation is 13.6 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight.

Give your answers as decimals, to two places

< μ <

Answer 1

Solution :

Given that,

Sample size = n = 32

Z/2 = 1.96

Margin of error = E = Z/2* ( /n)

= 1.96 * (13.6 / 32)

Margin of error = E = 4.71

At 95% confidence interval estimate of the population mean is,

- E < < + E

79 - 4.71 < < 79 + 4.71

74.29 < < 83.71