What’s the answer to this?v

Can someone me out here number 4 plz

Which equation expression the relationship between the number of boxes b and the number of cans c and the proportion is 48

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?