posted by Laynette on .
The diameters of grapefruits in a certain orchard are normally distributed with a mean of 6.45 inches and a standard deviation of 0.45 inches. Show all work.
(A) What percentage of the grapefruits in this orchard have diameters less than 7.1 inches?
(B) What percentage of the grapefruits in this orchard are larger than 6.8 inches?
Z = (score-mean)/SD = (score-6.45)/.45
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to these Z scores. Multiply by 100 to get percentage.