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Statistics question driving me crazy!

pinkdaffodil

New member
Joined
Oct 27, 2009
Messages
2
Please if anyone can help me figure this question out I would greatly appreciate it.

The mean height of a group of 900 men is 74. The standard deviation is 4. What height would a man be if he is in the 95th percentile.

I don't even know where to begin. I keep thinking it has something to do with the z-score, but I'm not sure. Any help would be great.

Thanks :)
 

galactus

Super Moderator
Staff member
Joined
Sep 28, 2005
Messages
7,216
If he is in the 95th percentile, that means he is taller than 95% of the other men in the group of 900. That means he is in the top 5%.

Look up the z-score for .95 is 1.645.

Using \(\displaystyle 1.645=\frac{(x-74)\sqrt{(900)}}{4}\) and solve for x.
 

pinkdaffodil

New member
Joined
Oct 27, 2009
Messages
2
Thank you so much!! I couldn't figure out where to start :) I got it now!
 
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