Age of College Students Find the 98% confidence intervals for the variance and standard deviation of the ages of seniors at Oak Park College if a random sample of 22 students has a standard deviation of 2.2 years. Assume the variable is normally distributed. Use the chi-square distribution table to find any chi-square values to three decimal places. Round the final answers to one decimal place. 2 Wi-Fi Access A survey of 40 students in grades 4 through 12 found 65% have classroom Wi-Fi access. Find the 90% confidence interval of the population proportion. Use a graphing calculator and round the answers to at least three decimal places. Dance Company Students The number of students who belong to the dance company at each of several randomly selected small universities is shown below. Estimate the true population mean size of a university dance company with 96% confidence. Assume the variable is normally distributed. Use a graphing calculator and round the answers to at least one decimal place. 32 25 21 22 28 30 26 30 47 26 35 26 35 29 28 28 32 27 Send data to Excel Exer Freshmen GPAs First-semester GPAs for a random selection of freshmen at a large university are shown. Estimate the true mean GPA of the freshman class with 90% confidence. Assume = 0.62. Round intermediate and final answers to two decimal places. Assume the population is normally distributed. 2.7 2.9 2.0 3.2 1.9 2.8 2.2 4.0 1.9 2.8 2.0 2.7 3.9 3.8 3.5 2.7 3.1 3.8 3.0 3.2 2.8 2.7 2.5 1.9 Send data to Excel Cost of Pizzas A pizza shop owner wishes to find the 99% confidence interval of the true mean cost of a large plain pizza. How large should the sample be if she wishes to be accurate to within $0.16? A previous study showed that the standard deviation of" the price was $0.46. Round your final answer up to the next whole number. The owner needs at least a sample of pizzas.