While installing a sprinkler system, ethel wants to cut a 20-foot length of plastic tubing into two pieces. the longer piece is to be 2 feet longer than twice the shorter piece. find the length of each piece.

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?