Tina brings cupcakes to class one day. she gives 2/5 of them to her friends amanda rachel and carlene. tina gave them 12 cupcakes. ryan saw an equation to determine the number of cupcakes tina brought to the class.

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?