A simple random sample of size n is drawn from a population that is known to be normally distributed. The sample variance, s , is determined to be 13.3. Complete parts (a) through (c). (a) Construct a 90% confidence interval for of if the sample size, n, is 20. The lower bound is . (Round to two decimal places as needed.) The upper bound is .(Round to two decimal places as needed.) (b) Construct a 90% confidence interval for o if the sample size, n, is 30. The lower bound is . (Round to two decimal places as needed.) The upper bound is . (Round to two decimal places as needed.) How does increasing the sample size affect the width of the interval? The width decreases O The width increases O The width does not change (c) Construct a 98% confidence interval for of if the sample size, n, is 20. The lower bound is . (Round to two decimal places as needed.) The upper bound is . (Round to two decimal places as needed.) Compare the results with those obtained in part (a). How does increasing the level of confidence affect the confidence interval? O The width decreases The width increases The width does not change Time Remaining: 02:36:39 Next Statcrunch 7:18 PM 53F Mostly cloudy 12/16/2021