# What is the F-Test, with regards to variances in populations being the same?

What is the F-Test, with regards to variances in populations being the same? (Include some examples)

A study of the effect of weathering on the radioactivity of granite was made by collecting a random sample of weathered rocks & another random sample of freshly exposed rocks. Measurements were made of the amount of radioactivity emitted in periods of one minute & the following data was obtained.

Fresh rocks 225 188 165 211 178 171 199

Weathered rocks 177 170 140 132 168 172 170

i) Examine the data for evidence of the effect of weathering & find a 95% confidence interval for the difference in mean radioactivity.

ii) State any assumptions you made in part i).

iii) Use an F-Test to justify one of the assumptions in part ii).

https://brainmass.com/statistics/f-test/ftest-variances-populations-same-14062

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A study of the effect of weathering on the radioactivity of granite was made by collecting a random sample of weathered rocks & another random sample of freshly exposed rocks. Measurements were made of the amount of radioactivity emitted in periods of one minute & the following data was obtained.

Fresh rocks 225 188 165 211 178 171 199

Weathered rocks 177 170 140 132 168 172 170

i) Examine the data for evidence of the effect of weathering & find a 95% confidence interval for the difference in mean radioactivity. ...

#### Solution Summary

A 95% confidence interval is found for a set of data. An F-test is employed to verify assumptions. The solution is comprehensive.