A car company says that the mean gas mileage for its luxury sedan is at least 21 miles pe sample of 8 cars has a mean gas mileage of 20 mpg and a standard deviation of 3 mpg. At a= 0.10, test the company's claim. Assume the populaiUI distributed. Click here to view the t-distribution table. Click here to view page 1 of the normal table Click here to view page 2 of the normal table H, p<21 H p>21 What is the value of the standardized test statistic? The standardized test statistic is. (Round to two decimal places as needed.) What is the critical value? The critical value is (Round to three decimal places as needed.) What is the outcome and the conclusion of this test? Ho At the 10% significance level, there is V evidence to ▼ the car company's claim that the mean gas mileage for the sedan is at least 21 miles per gallon.

The time it needs a communications worker to arrange a domestic phone call is normally distributed with mean  Fifty seconds and a standard deviation of  Eight seconds. Find the proportion of times that someone has to wait for more than a minute for the call to be placed.

Response time is an important statistic for measuring the effectiveness of a fire department, and is measured as the difference between the time a fire station receives a call and the time the first piece of fire equipment leaves the station. The response times for fire departments in a large city are found to have an approximately Normal distribution, with a mean of 4.5 minutes and a standard deviation of 1.2 minutes. What percentage of fire station response times are under 3 minutes? Find the z-table here. https://r03.core.learn.edgenuity.com/contentviewers/Emissary/OpenEmissaryLink/?a=http%3A%2F%2Fmedia.edgenuity.com%2Fcontentengine%2Fcommon%2F%2Fpassages%2F3112%2F1-3112-common-docs%2F3112-z-table.html&t=111000000000&l=&s=f2b2af05-7f11-ec11-8255-ef70046ba7f2 6.68% 10.56% 89.44% 93.32%

Head circumferences of some males have a bellshaped distribution with a mean of 57 centimeters and a standard deviation of 3 centimeters. What is the variance of head circumferences of adult males?