Which of the following sequences is not arithmetic? 1, 2, 3, 4, ... © 1, 4, 9, 16, ... O2, 4, 6, 8, ... O0,-2, -4, -6, ..​

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?