Alocal hamburger shop sold a combined total of 760 hamburgers and cheeseburgers on wednesday. there were 60 more cheeseburgers sold than hamburgers. how many hamburgers were sold on wednesday?

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?