A). For a standardized psychology examination intended for psychology majors, the historical data show that scores have a mean of515

and a standard deviation of170

. The grading process of this year's exam has just begun. The average score of the40

exams graded so far is518

. What is the probability that a sample of40

exams will have a mean score of518

or more if the exam scores follow the same distribution as in the past?

Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places.

B). The distribution of scores on a standardized aptitude test is approximately normal with a mean of480

and a standard deviation of95

. What is the minimum score needed to be in the top20

%

on this test? Carry your intermediate computations to at least four decimal places, and round your answer to the nearest integer.