Pick the expression that matches this description:
a 3^rd degree binomial with a constant term of 8
choose 1
(choice a)
8x^3+2x+3
(choice b)
2x^8+3
(choice c)
-5x^3+8
(choice d)
x^3-x^2+8

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?