Question

Ford claims that its Spiffy Sedan averages 31 mpg on the highway. Harold believes that Ford is exaggerating and the Spiffy in fact averages less than 31 mpg. Harold randomly selects 8 Super Spiffys from local car dealerships and tests their gas mileage on the highway. He finds the following mpg scores:

Calculate the mean and standard deviation of the sample data, and then test Harold’s claim at the 0.05 level of significance.

Ford claims that its Spiffy Sedan averages 31 mpg on the highway. Harold believes that Ford is exaggerating and the Spiffy in fact averages less than 31 mpg. Harold randomly selects 8 Super Spiffys from local car dealerships and tests their gas mileage on the highway. He finds the following mpg scores:

Calculate the mean and standard deviation of the sample data, and then test Harold’s claim at the 0.05 level of significance.

30, 28, 32, 26, 33, 25, 28, 30

Answer 1