Question

During the summer months, the prices of nonsmoking rooms with a king-sized bed in hotels in a certain area are roughly Normally distributed with a mean of $131.80 and a standard deviation of $29.12. A travel agent randomly selects prices of nonsmoking rooms with a king-sized bed from 15 hotels in the area. What is the probability that their average cost will be more than $150?
a) 0.0077
b) 0.3678
c) 0.2660
d) 0.1125

Answer 1

C

If you have a graphing calculator, go to 2nd vars, normalcdf(.

Put 150 for the lower bound and 99999999 for the upper bound. You want to know the probability of all the values over 150. Put 131.8 for the mean and 29.12 for the standard deviation. Click paste.

Your answer will be .266