normal random variable

[kim270]

suppose the height in inches of men is a normal random variable with mean=71 and variance = 6.25. what percentage of men are over 6 feet 2 inches? what percentage of men in the 6 footer clubare over 6 feet 5 inches?

for the 1st part i got:

p(x>74)=p(z>1.2)
p(x>74)=0.1151
p(x>74)= 1.151%

and for the 2nd part i got

p(x>74)= 0.0062
p(x>74)= 0.62%

i was wondering if someone could check these for me please

 

[soroban]

Hello, kim270!

One tiny error . . . and a more serious one . . .

Suppose the height in inches of men is a normal random variable with mean=71 and variance = 6.25.
What percentage of men are over 6 feet 2 inches?
What percentage of men in the 6 footer clubare over 6 feet 5 inches?

for the 1st part i got:
. . \(\displaystyle p(x>74)\:=\(z>1.2)\:=\:0.1151\:=\:1.151%\) . . . . Of course, you meant 11.51%


and for the 2nd part i got:
. . \(\displaystyle p(x>77)\:=\:0.0062\:=\:0.62%\) . ??

\(\displaystyle p(x>77)\:=\(z>2.4)\:=\:0.0082\:=\:0.82\%\)