Posted by florence on .
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.

statistics 
Kuai k,
z = (125123)/(9.6/sqrt(144)
z = 2/(9.6/12)
z = 2.5
ztable
1.0062 =0.9938