(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The electricity usage (KWh) in homes was studied over a period of time.

For Year 1:

Mean = 1130

Std dev. = 196

n = 16

For Year 2:

Mean = 1350

Std dev. = 302

n = 21

a)

Test the hypothesis that the std dev. in year 2 has increased compared to year 1. Remember to state your significance level.

b)

Test the hypothesis that the std dev. in year 1 and 2 are equal. Remember to state your significance level.

2. Relevant equations

3. The attempt at a solution

I don't know about a) really.

For b) I think the F-distribution could be used, right?

But what significance level should I use? Someone help me get started on this?

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# Homework Help: Statistics, hypothesis test

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