I need help on this question for my stats class plz

Question

You measure 36 textbooks' weights, and find they have a mean weight of 37 ounces. Assume the population standard deviation is 10.4 ounces. Based on this, construct a 99% confidence interval for the true population mean textbook weight. Round answers to at least 4 decimal places.

Answer 1

CI = mean +/- critical value for 99% CI * standard deviation/square root(sample size)

critical value for 99% CI is found by looking up z-score for probability 0.995 ~= 2.58

mean is given as 37, standard deviation is given as 10.4 and sample size is given as 36.

plug numbers into formula get CI.