Question

In a study of wait at an amusement park, the most popular roller coaster has a mean wait time of 17.4 minutes with a standard deviation of 5.2 minutes. If 14 days are randomly selected, find the probability that the mean wait time is between 10 & 20 minutes.

A: 0.9693
B: 0.0471
C: 0.6713
D: 0.9470

Answer 1

Answer 0.6713

Explanation:

Answer 2

Option A is right

0.9693

Explanation:

X is a random variable

X is normal with mean time = 17.4 minutes

Std deviation = 5.2 minutes

No of days = 14

Sample size =14

Std error =std dev /sq rt 14

=1.39

Required probability

=P(10<x<20)

=P(-7.4/1.39<z<2.6/1.39)

= P(-5.32<z<1.87)

=0.9693

Option A is right