Answer:
Step-by-step explanation:
Let X be the mean height of peak patrons,
Then X is normal with mean = 68 inches and std dev = 12 inches
Whenever x<54, they are not allowed to use the ride.
x=54 means z=
The z for 54" is
From std normal table we find that the area to the left of -1.17 is
0.3790
P(X>54) =1-0.3790
=0.6210=62.10%
P(54<x<68) = 0.5-0.3790 =0.121=12.1%
P(X>68) =0.5%=50%