Is the function y = 3x + 7 a proportional relationship? if it is, what is the slope of the line? a. this is a proportional relationship. the slope is 3 7 . b. this is a proportional relationship the slope is 7 3 . c. this is a proportional relationship. the slope is 3. d. this is not a proportional relationship.

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?