Question

You measure 25 textbooks' weights, and find they have a mean weight of 30 ounces. Assume the population standard deviation is 5.2 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

Since the population standard deviation is known z statistic is used to calculate the 95% confidence interval,

The 95% confidence interval for the population mean is given by,

Where,

The critical value for the z statistic is obtained from z distribution table for 95% confidence level,