Suppose 1 and 2 are true mean stopping distances at 50 mph for cars of a certain type equipped with two different types of braking systems. The data follows: m = 7, x = 114.9, s1 = 5.07,
n = 7, y = 129.7, and s2 = 5.34. Calculate a 95% CI for the difference between true average stopping distances for cars equipped with system 1 and cars equipped with system