A Company Makes a Device That Can Be Fitted to Automobile

Essay

A company makes a device that can be fitted to automobile engines to improve the mileage. The company claims that if the device is installed, owners will observe a mean increase of more than 3.0 mpg. Assuming that the population standard deviation of increase is known to be 0.75 mpg, and a sample of size 64 cars is selected, what is the probability of "accepting" the null hypothesis if the true population mean is 3.10 mpg increase? Assume that the test will be performed using a 0.05 level of significance.