The area of a triangle is 1600. Two of the side lengths are 65 and 67 and the included angle is obtuse. Find the measure of the included angle, to the nearest tenth of a degree.

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?