Two college roommates have each committed to donating to charity each week for the next year. The roomates' weekly incomes are independent of each other. Suppose the amount donated in a week by one roommate is approximately normal with mean $30 and standard deviation $10, and the amount donated in a week by the other roommate is approximately normal with mean $60 and standard deviation $200. Which of the following is closest to the expected number of weeks in a 52-week year that their combined donation will exceed $120?
(A) 0; the combined donation never exceeds $120 in a week
(B) 1 week
(C) 3 weeks
(D) 5 weeks (answer)
(E) 8 weeks
from a released AP Stat. multiple choice. Thank you!
(A) 0; the combined donation never exceeds $120 in a week
(B) 1 week
(C) 3 weeks
(D) 5 weeks (answer)
(E) 8 weeks
from a released AP Stat. multiple choice. Thank you!
