Based on the number of pyramids that fit precisely into a cube, which of the following is used in an informal argument for the formula for the volume of a pyramid? a) v = b cubed over 2 b) v = b cubed over 3 c) v = b cubed over 4 d) v = b cubed over 6

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?