0/14 Question 1 of 14, Step 1 of 1 3 Correct A professor wants to estimate how many hours per week her students study. A simple random sample of 80 students had a mean of 17 hours of studying per week. Construct a 90 % confidence interval for the mean number of hours a student studies per week. Assume that the population standard deviation is known to be 2.3 hours per week. Round to two decimal places. Answer Tables Keypad Keyboard Shortcuts Lower Endpoint: Upper Endpoint