According to a recent survey, the salaries of assistant professors have a mean of $41,750 and a standard deviation of $7000 . assuming that the salaries of assistant professors follow a normal distribution, find the proportion of assistant professors who earn more than $48,000 . round your answer to at least four decimal places.

Respuesta :

To get the proportion of professors who earn more than $ 48,000 we proceed as follows;
z=(x-mean)/s.d
x=48000
mean=41,750
s.d=7000
thus;
z=(48000-41750)/7000
=0.8929
the probability associated with z-score is:
P(48000)=0.8133
thus the probabilty of those who are earning more than $48,000 will be:
1-0.8133
=0.1867