# statistics

A normal distribution has a mean = 100. Find its standard deviation if 17% of the values exceed 144.

All I can say is wow. Book is of no help. Neither is teacher. Can anyone help?

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1. This also relates to the Z score and the table discussed in your other post.

In the table, find the Z score in which .17 of the distribution fall in the smaller portion. Put that Z value and the other values in the Z score formula and solve for the SD.

I hope this helps. Thanksfor asking.

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