Posted by Brittany on .
An important measure of the performance of a locomotive is its "adhesion," which is the locomotive's pulling force as a multiple of its weight. The adhesion of one 4400-horsepower diesel locomotive model varies in actual use according to a Normal distribution with mean μ = 0.39 and standard deviation σ = 0.036
What proportion of adhesions (± 0.001) measured in use are higher than 0.32?
What proportion of adhesions (± 0.001) are between 0.32 and 0.45?
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores.