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Chapter 7: Q.19 (page 428)

Find the sum with a z–score of -2.5.

Short Answer

Expert verified

The sum with az-score of-2.5is∑X=3903.5.

Step by step solution

01

Given Information

A sample size (n)=100.

The mean of population μX=39.01.

z=-2.5.

A standard deviation σX=0.5.

02

Explanation

To find the sum with a z-score of -2.5:

∑X=(n)μX+(z)(n)σX

Calculating, we have:

∑X=100×39.01-2.5×100×0.5

∑X=3888.5

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