Satistics
posted by Benjamin on .
In North American, female adult heights are approximately normal with a mean of 65 inches and a standard deviation of 3.5 inches.
a.) If one female is selected at Random, what is the probablility that shes has a height 70 inches or higher?
b.) The heights of 50 females were measured at a national collegiate volleyball tournament. The sample mean height was found to be 70 inches. using the population parameters given above, what is the probability of botaining a sample mean height of 70 inches or higher with a random sample of 50 females?
c.)Does the probability you found in (b) make you question the population mean stated for female heights? Justify why you believe this sample mean may not be representative of the population of female heights?

a. Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score.
b. This is a distribution of means rather than raw scores.
Z = (Sample mean population mean)/SEm
SEm (standard error of the mean) = SD/√(n1)
Use same table.
c. Might volleyball players be a biased sample?