INFO: An elevator serving a hospital is designed to hold up to 15 passengers and

ID: 3249256 • Letter: I

Question

INFO: An elevator serving a hospital is designed to hold up to 15 passengers and has a maximum safe

capacity of 2440 pounds. The weight of passengers who use the elevator is normally-distributed

with an average of 149 pounds and a standard deviation of 20 pounds.

Question 17: What is the probability that a single passenger on the elevator weighs between 140 and 150

pounds? Correct Answer= .1935

Question 18: What is the probability that a single passenger on the elevator weighs more than 200 pounds? Correct Answer= .0054

Question 19: If five passengers enter the elevator together, what is the probability that exactly four of them

weigh 200 pounds or less? Correct Answer= .0264

Question 20: If we consider only elevator trips which carry 8 passengers, how many of these passengers, on

average, weigh 200 pounds or less? Correct Answer= 7.9568

QUESTION 21 PLEASE HELP: What is the probability that the elevator’s safe capacity is exceeded by a full load of 15

passengers?

21) average weight of 15 customer=149*15=2235

std deviation =20*(15)1/2 =77.46

hence

probability that the elevator’s safe capacity is exceeded by a full load of 15

passengers =P(X>2440)=1-P(X<2440)=1-P(Z<(2440-2235)/77.46)=1-P(Z<2.6465)=1-0.9959=0.0041