The mean of a distribution of scores is equal to 13 with a standard deviation of Sx = 6. If 10 points are added to each of the values in the distribution, the new mean and standard deviation will be: *

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?