Finding a Critical F-Value for a Right-Tailed Test

Question

Finding a Critical F-Value for a Right-Tailed Test In Exercises 5–8, find the critical F-value for a right-tailed test using the level of significance α and degrees of freedom d.f.N and d.f.D.

α=0.10, d.f.N=10, d.f.D=15

Accepted Answer

Hello there. Today we're gonna solve the following practice problem together. So first off, let us read the problem and highlight all the key pieces of information that we need to use in order to solve this problem. Determine the critical F value for a right tail test where alpha equals 0.01, DFN equals 5, and DFD equals 25. Awesome. So it appears for this particular prom, we're asked to ultimately determine what the critical F value is for this specific right tail test given the values provided to us by the prom itself. Or rather, the known variables that are provided to us by the problem itself. So, now that we know that we're ultimately trying to figure out what this critical F value is, let's read off our multiple choice answers to see what our final answer might be. So, A is 2.876, B is 5.057. C is 4.180 and D is 4.060. So now that we've looked at our multiple choice answers, our first step that we need to take in order to solve this problem is we need to write down all of our known variables. So we're told that our level of significance alpha is equal to 0.01. We're also told that our degrees of freedom for the numerator, which is gonna be denoted as DFN. is equal to 5 and the degrees of freedom for the denominator, which we'll call DFD, is equal to 25. So once again, our degrees of freedom for the numerator is equal to 5, and the degrees of freedom for the denominator is equal to 25. Our second step now is we need to recall how to use a F table or a calculator in order to determine what the critical value is for these particular parameters. So I'll make a note that we're using a F table, which I'll call FT. So now that we know that we're trying to recall how to use an F table, which you should have an F table in your textbook or you can quickly look one up online, or you could use your calculator, but using your F table or your calculator, you'll be able to determine that the critical F value will be. F subscript 0.01525 will be approximately equal to 4.180. So that is our final answer. Hooray, we did it. So looking at our multiple choice answers, this corresponds to multiple choice answer letter C, which once again is 4.180. Thank you so much for watching. Hopefully that helped, and I can't wait to see you in the next video. Bye.

Finding a Critical F-Value for a Right-Tailed Test In Exercises 5–8, find the critical F-value for a right-tailed test using the level of significance α and degrees of freedom d.f.N and d.f.D.

α=0.10, d.f.N=10, d.f.D=15

Key Concepts

F-Distribution

Critical Value

Degrees of Freedom

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