statistics question

Question

You measure 36 textbooks' weights, and find they have a mean weight of 70 ounces. Assume the population standard deviation is 9.6 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight .

Answer 1

95% CI = mean +/- z-critical value * population standard deviation/square root (sample size)

mean is given as 70, z-critical value is 1.96, population standard deviation is given as 9.6 and sample size given as 36.

plug values into formula and you'll have your answer