Two ships, one sailing at 10mi/h and the other at 15mi/h, left port at the same time. Three hours later they were 40mi apart. If you had to find the angle between their courses, an equation that could be used to solve this problem is:

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?