18. A new college entrance exam scores designed so that for a reference population they are
distributed normally, with mean 650 and standard deviation 125. Based on this
information:
a. What percentage of students in the reference population scored above 775?
b. Between what two scores did the middle 95%of the reference population score?
c. Out of every 1,000 people in the reference population, approximately how many
scored below 525?