Suppose the wait to pass through immigration at JFK Airport in New York is thought to be bell-shaped and symmetrical with a mean of 19 minutes. It is known that 68% of travelers will spend between 5 and 33 minutes waiting to pass through immigration. The standard deviation for the wait time through immigration is _________.Multiple Choice18 minutes17 minutes14 minutes16 minutes

Suppose the commute times for employees of a large company follow a normal distribution. If the mean time is 22 minutes and the standard deviation is 5 minutes, 95% of the employees will have a travel time within which range?A.17.25 minutes to 26.75 minutesB.17 minutes to 27 minutesC.12 minutes to 32 minutesD.7 minutes to 37 minutesSUBMITarrow_backPREVIOUS

The manager of a grocery store has taken a random sample of 100 customers to determine whether or not the mean waiting time of all customers is significantly more than 3 minutes. She observes that the average length of time it took the customers in the sample to check out was 3.1 minutes. The population standard deviation is known to be 0.5 minutes.

The waiting time to check out of a supermarket has had a population mean of 8.49 minutes.Recently,in an effort to reduce the waiting time,the supermarket has experimented with a system in which there is a single waiting line with multiple checkout servers.A sample of 90 customers was selected,and their mean waiting time to check out was 7.85 minutes with a sample standard deviation of 4.9 minutes.Complete parts(a)through(d) H0:μ≥8.49 H1:μ<8.49 What is the test statistic for this test? -1.2391 (Round to four decimal places as needed.) What is the critical value for this test?

The post office, which has separate lines at different windows, determines that the standard deviation for customer waiting times on Friday afternoons is 7.2 minutes. The post office decides to experiment with a single, main waiting line. For a random sample of 25 customers, it is found that the waiting times have a standard deviation of 3.5 minutes on a Friday afternoon. At a 5% significance level, the post office wants to test the assertion that a single line results in less variation in waiting times for customers. Give your conclusion.

The amount of time workers spend commuting to their jobs each day in a large metropolitan city has a mean of 70 minutes and a standard deviation of 20 minutes. Assuming nothing is known about the shape of the distribution of commuting times, what percentage of these commuting times are between 30 and 110 minutes?Group of answer choicesat least 95%at least 89%at least 0%at least 75%