Less. c. Compute the probability of a value between 55.0 and 70.0.
19. 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 $3,500?
c. What percent of the refunds are more than $2,500 but less than $3,500?
of 20 million with a standard devi-
an
The number of viewers of American Idolben​