Respuesta :

The value of x² values that separate the middle 80 % from the rest of the distribution is

With alpha  and  degrees of freedom χ²= 12.443

And with alpha  and  degrees of freedom χ²= 28.412

Chi - Square Distribution:

The chi square distribution is the continuous distribution, where the degree of freedom is the sample size minus 1, and it is the parameter of the chi-square probability distribution.

Given,

Here we need to find the value of x² values that separate the middle 80 % from the rest of the distribution for 20 degrees of freedom.

Based on the given details,

Degrees of freedom = 20

Middle separate value = 80%

Which is equal to 0.8 in decimal point.

The significance level

=> ∝ = 1 - 0.8

=> ∝  = 0.2

But we need the area of the middle so we divide this significance level with 2

so that we get exactly the middle area .

Dividing

=> 0.2/2= 0.1

So we will have two values for chi square

One with  

=> 0.8 + 0.1 = 0.9 alpha

and

one with

=> 0.1 alpha .

This is because the chi square is right tailed.

Now based on the chi square distribution table,

So with alpha 0.9 and 20 degrees of freedom χ²= 12.443

And with alpha 0.1 and 20 degrees of freedom χ²= 28.412

To know more about Chi square distribution here.

https://brainly.com/question/17031122

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