In: Statistics and Probability
A survey found that women's heights are normally distributed with mean 63.9in. and standard deviation 3.1 in. The survey also found that men's heights are normally distributed with mean 68.7 in. and standard deviation 3.7 in. Most of the live characters employed at an amusement park have height requirements of a minimum of 57 in. and a maximum of 63in. Complete parts (a) and (b) below.
The percentage of men who meet the height requirement ?
If the heigh requirements are changed to exclude only the tallest 50% of men and the shortest 5% of men what are the new height requirements?
Given:
For women :
Mean = = 63.9
Standard deviation = = 3.1
Let X be the women's heights are normally distributed.
For men :
Mean = = 68.7
Standard deviation = = 3.7
Let X be the men's heights are normally distributed
Ansa:
The percentage of men who meet the height requirement ?
ie P(57<x<63)
For men :
Mean = = 68.7
Standard deviation = = 3.7
P(57<x<63)=P((57-68.7)/3.7<(x-)/<(63-68.7)*/3.7)
=P(-3.162<z<-1.5405)
=P(z<-1.5406)-P(z<-3.162)
=0.06171-0.0008
=0.0609
# 6.09% of men who meet the height requirement
Ansb:
P(z<z)0.05
P(z<-1.645)=0.05
z=-1.645
from z-score formula.
x1=+z*
=68.7+(-1.645*3.7)
x1=62.61
P(z>0)=0.5
ie z=0
from z-score formula.
x2=+z*
=68.7+(0*3.7)
=68.7
x2=68.7