The area of europe is approximately 9.94 × 106 square kilometers. its population is approximately 7.31 × 108 people. what is the approximate population density (people per square kilometer) of europe? write your answer in standard form. if necessary, round your answer to the nearest hundredth.

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?