#15

E Homework: Section 6.4 Confidence Intervals for Question 15, 6.4.23-T HW Score: 56.82%, 12.5 of 22 points Variance and Part 3 of 4 O Points: 0 of 1 Save The waiting times (in minutes) of a random sample of 21 people at a bank have a sample standard deviation of 4.5 minutes. Construct a confidence interval for the population variance of and the population standard deviation a. Use a 90% level of confidence. Assume the sample is from a normally distributed population. What is the confidence interval for the population variance of? ( 12.9 . 37.3 ) (Round to one decimal place as needed.) Interpret the results. Select the correct choice below and fill in the answer box(es) to complete your choice. (Round to one decimal place as needed.) A. With 90% confidence, you can say that the population variance is between 12.9 and 37.3 O B. With 10% confidence, you can say that the population variance is between and O C. With 90% confidence, you can say that the population variance is less than O D. With 10% confidence, you can say that the population variance is greater than What is the confidence interval for the population standard deviation a? [(Round to one decimal place as needed.)