In a large section of a statistics class, the points for the final exam are normally distributed, with a mean of 70 and a standard deviation of 8 Grades are to be assigned according to the following rule

. the top 10% receive A's, the next 20% receive B's;

the middle 40% receive C's the next 20% receive D's,

the bottom 10% receive F's

Find the lowest score on the final exam that would qualify a student for an A, a B: a C, and a D.

1 answer

You can play around with Z table stuff at
davidmlane.com/hyperstat/z_table.html