Preston, an official for a state’s department of safety, wants to show that the population mean speed of passenger

Preston, an official for a state’s department of safety, wants to show that the population mean speed of passenger

vehicles traveling on a certain expressway is greater than the posted speed limit of 65mph. Preston collects a random sample of 59 passenger vehicles traveling on the expressway and finds that the sample mean speed is 67.1mph

with a sample standard deviation of 7.5mph. The test statistic t for a hypothesis test of H0:?=65 versus Ha:?>65 is t?2.15

with 58 degrees of freedom. If 0.01