In: Math
The grades of a group of 1000 students in an exam are normally distributed with a mean of 70 and a standard deviation of 10. A student is randomly selected from the group. Find the probability that;
a. Their grade is greater than 80
b. Their grade is less than 50
c. That their grade is between 50 and 80
d. Approximately, how many students have grade greater than 80% and how many have less than 50%