Is each pair of expressions equivalent? select yes or no. a. 8(−2 + −4) and −2(−8 − 12) b. −4(−2 + 3) and 2(4 − 6) c. −(−3)(−2 + −10) and 2(−3 − 15)

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?