In the problem above you were given the height and asked to find the percentile.

Question

In the problem above you were given the height and asked to find the percentile. Now, you'll be going in the opposite direction-- you'll be given the percentile (placement on the normal curve) and asked to find the height. In both cases the first step is to find the z-score.

If someone is in the 92 th percentile in height (i.e., is taller than 92 % of the other males in the class), let's work on finding his height. First we'll find the z score.

(Do NOT look up the z score for Area= 92 % on the table b/c the Areas given on the table are MIDDLE areas. 92 th percentile means 92 % to the LEFT, and 8 % in the right tail.)

What is the Z-score corresponding to the middle area?

(If the middle area falls between two lines on the table, you may use the closest one. Put Z-score in blank below.)1.41

Now change the z score to a height. (Remember the z score tells how many SD's the value is from the average. So a z score of 2 means the person is 2 SDs above average which would be 2*(2.5") + 70.5".)

What is his height?

"

If someone is in the 8 th/st percentile in height (i.e., is taller than only 8 % of the other males in the class), let's find his height.

First find the Z score.

Explanation / Answer

( please confirm mean =70.5 and std deviation =2.5)

here as z score for 92th percentile =1.41

therefore corresponding height =mean+z*std deviaiton =70.5+2.5*1.41=74.03

z score for 8th percentile = -1.41

therefore corresponding height =mean+z*std deviaiton =70.5-2.5*1.41=66.98

( please revert for any clarifciation)

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