Question

You measure 48 textbooks' weights, and find they have a mean weight of 78 ounces. Assume the population standard deviation is 2.1 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 = 48

Z_/2 = 1.96

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

= 1.96 * (2.1 / 48)

Margin of error = E = 0.59

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

- E < < + E

78 - 0.59 < < 78 + 0.59

77.41 < < 78.59