The valdez family left at noon for a 4-hour trip to visit relatives. they stopped 1 hour for lunch and 2 hours to visit an amusement park. what time did they get to their relatives' house?

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?