Suppose $\mu _ { 1 } \text { and } \mu _ { 2 }$

Essay

Suppose $\mu _ { 1 } \text { and } \mu _ { 2 }$ are true mean stopping distances at 50 mph for cars of a certain type equipped with two different types of braking systems. The following statistics are given: m = 6, $\bar { x } = 116 , s _ { 1 } = 5.0 , n = 6 , \bar { y } = 129 \text {, and } s _ { 2 } = 5.5$ Calculate a 95% CI for the difference between true average stopping distance for cars equipped with system 1 and cars equipped with system 2. Does the interval suggest that precise information about the value of this difference is available?