#12

Math-K300 Spring 2022 Online Kierstyn Cochran 03/27/22 9:27 AM Homework: Section 6.4 Confidence Intervals for Question 12, 6.4.19-T HW Score: 54.55%, 12 of 22 points Sa Variance and Part 3 of 4 Points: 0 of 1 As part of a water quality survey, you test the water hardness in several randomly selected streams. The results are shown below. Construct a confidence interval for the population variance o" and the population standard deviation a. Use 90% level of confidence. Assume that the population has a normal distribution. n = 18 s = 14 grains per gallon What is the confidence interval for the population variance of? 120.8 , 384.2 ) (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 places as needed.) O A. With 10% confidence, it can be said that the population variance is greater than B. With 90% confidence, it can be said that the population variance is between 120.8 and 384.2 O C. With 90% confidence, it can be said that the population variance is less than D. With 10% confidence, it can be said that the population variance is between and What is the confidence interval for the population standard deviation o? ()(Round to one decimal place as needed.)