Salaries for teachers in a particular elementary school district are normally distributed with a mean of $41,000 and a standard deviation of $6,400. We randomly survey ten teachers from that district.

A.

X~ ? P U N G B (______, __________)

B.

Find the probability that the teachers earn a total of over $400,000. (Round your answer to four decimal places.)

C. Find the 90^th percentile for the sum of ten teachers' salary. (Round your answer to the nearest whole number.)