For a population that is left skewed with a mean of 22 and a standard deviation equal to 12, determine the probability of observing a sample mean of 20 or more from a sample of size 37. Click here to view page 1 of the Cumulative Standardized Normal Table. Click here to view page 2 of the Cumulative Standardized Normal Table. What is the probability of observing a sample mean of 20 or more from a sample of size 37? P(x220): (Round to four decimal places as needed.) A survey of 34 college freshmen found that they average 6.98 hours of sleep each night. A 95% confidence interval had a margin of error of 0.519. a. What are the lower and upper limits of the confidence interval? b. What was the standard deviation, assuming that the population standard deviation is known? ... a. The lower limit of the confidence interval is 6.461 and the upper limit of the confidence interval is 7.499. (Round to three decimal places as needed.) b. The standard deviation, assuming that the population standard deviation is known, is (Round to three decimal places as needed.) Construct a 98% confidence interval to estimate the population mean when x = 131 and s = 28 for the sample sizes below. a) n = 40 b) n = 70 c) n = 100 Click here to view page 1 of the critical t-score table. Click here to view page 2 of the critical t-score table.