Rectangle QRST with vertices Q(-6,-1), R(-3,1), S(1,-5), T(-2,-7) (x, y) =
x+5, y+7

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?