What is the solution to the system of equations below? y=-3x-9 and y=1/3x-39 a. (9, -36) b. (9,0) c. (-9, 18) d. (-9, -42)

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?