USE THE INFORMATION BELOW TO ANSWER QUESTIONS 31 THRU 33 The U.S. Census Bureau estimates that American workers spend an average time of 27 minutes travel time to work. The travel time to work for American workers is known to be approximately normally distributed. A random sample of 20 American workers in the Chicago metropolitan area was taken and their travel times to work were recorded. Question 31 1 pts Choose the formula that should be used to calculate a confidence interval for the true mean travel time to work for American workers in the Chicago metropolitan area. O Can't answer this question based on the information given. x +z- Vn p(1 - p P + z1 Vn O None of these are correct.Question 32 1 pts For a 92% confidence interval pick the appropriate z or t value that would be used. 1.85 O 1.88 O 1.80 O 1.76 Question 33 1 pts If we have a data set where the shortest travel time is 8.0 minutes and the longest travel time is 62.8 minutes, what is an acceptable estimate for the value of the sample standard deviation of the travel times in the sample? Assume answers are rounded to the nearest tenth of a minute. O 8.9 O 9.1 0 9.2 O 9.4