We are interested in determining whether or not the variances of the sales at two small grocery stores are equal. A sample of 21 days of sales at Store A and a sample of 16 days of sales at Store B indicated the following Store A Store B nA=21 nB=16 SA=28.284 SB=20 The test statistic is .

Step-by-step explanation:

Data given and notation  

represent the sampe size for A

represent the sample size for B

represent the sample deviation for A

represent the sample deviation for B

represent the significance level provided

F test is a statistical test that uses a F Statistic to compare two population variances, with the sample deviations s1 and s2. The F statistic is always positive number since the variance it's always higher than 0. The statistic is given by:

Solution to the problem  

System of hypothesis

We want to test if we have the same variation, so the system of hypothesis are:

H0:

H1:

Calculate the statistic

Now we can calculate the statistic like this:

In order to determine whether the variance of the sale of 2 small grocery stores is equal.

The sample of 21 days is used for sales at a store where the A is a sample and the 16 days of the sale in store B.

Learn more about the interest in determining.

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expression #3 is not equivalent. the others are.