Question: A test is conducted on the friction horsepower of engines lubricated with two commercial oils. The results of the experiment are:

SLICK-OIL mean = 12.4 n = 10 sample variance = 1.15

GO-CAR mean = 15.2 n = 13 sample variance = 0.75

a: At the .05 level of significance, would you conclude that Slick-Oil has a friction horsepower equal to that of Go-Car oil?

b: Construct a 95% confidence interval.