+0  
 
0
1460
1
avatar+530 

Use technology or a z-score table to answer the question.

The scores on a memory test are normally distributed with a mean of 100 and a standard deviation of 25. Consider a group of 400 people who take the test.

How many people will score 90 or less?

 

63

138

180

262

 May 22, 2018
 #1
avatar+107348 
+1

We have

 

[ 90  - 100 ]  / 25  =

 

-10 / 25  =

 

- 2 / 5  = 

 

- .4

 

The   table value for this z score  is  .3446

 

So

 

.3446  ( 400)  ≈  138  people

 

 

cool cool cool

 May 22, 2018

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