An engineer makes different-size samples of new material. The table shows volumes and the related masses. What would be the mass of 100 cubics centimeters of the material? Of 500 cubics centimeters of the material? Use a pencil and paper. Explain how you can use mental math to find the answer.

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?