An average grade of 80 on all exams in a course is needed to earn a b in the course. on her first four exams, chuck’s grades are 96, 65, 79, and 87. what is the minimum grade that chuck can receive on the fifth exam to earn a b in the course?

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?