Z = (mean1 - mean2)/SEm
SEm = SD/√n
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.
Assume that blood pressure readings are normally distributed with a mean of 123 and a standard deviation of
9.6. If 144 people are randomly selected, find the probability that their mean blood pressure will be less than 125
2 answers
0.9938
2 answers