Question 850:

Asked on March 5, 2010

Tags: ANOVA , ANOVA Table

1

Answer:

No answer provided yet.To answer this question you just need to know how the ANOVA table is assembled.

a. The number of treatment degrees of freedom are equal to the number of treatments minus one. So that means there are 3 treatments.
b. The total sample size will be one more than the total degrees of freedom. In this case there are 11, making the total sample size 12.
c. To find the critical value of F for an alpha of .05 we need to know the numerator degrees of freedom and the denominator degrees of freedom (since F is a ratio of the two). The numerator is the treatment degrees of freedom(2) and denominator is the Error df, which can be found as the total-treatment = 9. So we can use an F-table or the excel function =FINV(.05,2,9) to get the F critical value of 4.256. That means if an F-ratio above this value is obtained, there is a significant difference between the means at the .05 level.
d. The Null Hypothesis for an ANOVA is that there is no difference in the means between any of the populations being test. The Alternative Hypothesis is at least one means is difference than the other means.