Question: Prescott’s Oily Jones, manager of the Prescott We Lube it, knows that his industrial trade group found that people change their oil on average when they have gone more than 4,200 since their last oil change. To test this he does a random sample of 100 vehicles that come into his Lube Emporium for an oil change. He finds that the sample mean for these vehicles is 4,278 with a sample standard deviation of 780 miles. Write out the null and research hypothesis for this data and prove or disprove your null hypothesis with the significance level = .05.