Question

what is the error in the following report of F ratio? F(43)=420

a) p=0.0001

b) p<0.05

c) p<0.01

d) the level of significance is not indicated

Answer 1

Problem statement: Given information on degrees of freedom and the corresponsing F-value, we have to compute the associated p-value.

Given: We are provided with an information that F(43)=420. Based on this information we have to compute the associated p-value.

Solution: Correct option is (b).

The F-value obtained in this study is 420.This F-value is obtained using the ratio of degrees of freedeom which is 43 (given in the information).

To proceed further we have to refer to F-table. For a given ratio of numerator and denominator, which is 43 in this case, if we observe the F-stiaistic values at significance levels 0.05 and 0.01 we obtain F-statistic values of 251.3 and 6300 respectively.

For a given significance level (say 0.05,0.01), we say a statisitc is significant if the value of F-statistic observed is greater than the F-statistc value for that critical level(like 251.3 for 0.05 level).

In this case, 251.3<420<6300. Since 420> 251.3 and 420<6300, we coclude that p-value < 0.05. Correct option is (b).

Option (d) is NOT relevant since options are related to p-value and not fixed level significance testing.