According to a recent survey, the salaries of assistant professors have a mean of $40,756 and a standard devia

According to a recent survey, the salaries of assistant professors have a mean of $40,756 and a standard deviation of $8000. Assuming that the salaries of assistant professors follow a normal distribution, find the proportion of assistant professors who earn more than $50,000. Round your answer to at least four decimal places

According to a recent survey, the salaries of assistant professors have a mean of $40,756 and a standard devia
the general form of a normal distribution,


http://en.wikipedia.org/wiki/Normal_dist...


or gaussian distribution is:


(1/(s*sqrt(2*pi))) * exp(-((x-mu)^2)/(2*s*s))





what you are looking for is the integral from x=50k to x=inf





for an answer I got 12.3942%





You can also use a z table for this. To find your z you subtract the mean and divide by the standard deviation.





(50k-40.756k)/8k=1.1555





Try going to this link (http://davidmlane.com/hyperstat/z_table.... and entering 1.1555 into the above entry. You get the same answer displayed: 0.123943, or 12.3943%