SOLUTION: I am not understanding... A set of data is normally distributed with a mean of 100 and standard deviation of 15. · What would be the standard score for a score of

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Question 621444: I am not understanding...

A set of data is normally distributed with a mean of 100 and standard deviation of 15.
· What would be the standard score for a score of 90?
· What percentage of scores is between 100 and 90?
· What would be the percentile rank for a score of 90?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

Note:  Bell shaped Curve showing placement of z = 0, z = ±1, 2, 3 

Left or Right of z = 0 being 50% of the area under the standard normal curve...



As to A set of data is normally distributed with a mean of 100 and SD of 15. X = 90 

 z = (90-100)/15 =+-.6667

Exel function NORMSDIST(-.6667) = .25 , 25% to the left and 75% to the right

What percentage of scores is between 100 and 90? 25%

· What would be the percentile rank for a score of 90? 25%