1.A group of statistics students took a midterm exam. The class mean was 72 and the standard deviation was 3.2. The instructor decided to "curve" the grades based on their normal distribution. A grade of C was given if students were within one standard deviation of the mean. B's and D's were between one and two standard deviations, and A's and F's were outside of two standard deviations.

a)Using the rules of rounding and the normal curve, establish a grade scale for this exam. All grades should be rounded to a whole number.

A grade of A is between ______ and ______.

A grade of B is between ______ and ______.

A grade of C is between ______ and ______.

A grade of D is between ______ and ______.

A grade of F is between ______ and ______.

b)What letter grade would a score of 66 receive?

c)What letter grade would a score of 77 receive?

d)If there are 50 students in the class, how many scored a C?

e)If there are 40 students in the class, how many scored an A?