A researcher investigated the effect of volume of background noise on participants’accuracy rates while performing a difficult task. He tested three groups of randomly selected students and obtained the following means and sums of squares:

Question

Volume
Source Sum of sqs. df Mean sq
Between 652.16 ______ ______ ______
F_______
Within 612.75 ______ ______
total 1264.92 ______
(a) Complete the ANOVA. (b) At á = .05, what is Fcrit? (c) Report the statistical results in the proper format. (d) Perform the appropriate post hoc tests. (e) What do you conclude about this study? (f) Compute the effect size and interpret it.
Please help.... Thank you in advance

Answer 1

Looks like you might be filling in a table for a one-way ANOVA test.

Your ANOVA summary table has the following setup:

Source.....SS.....df.....MS.....F
Between
Within
Totals

Here are a few hints:

SS total = SS between + SS within

To calculate df between:
k - 1
Note: k = number of levels or groups.

To calculate df within:
N - k
Note: N = total number of values in all levels or groups.

df total = df between + df within

To calculate MS between:
SS between/df between

To calculate MS within:
SS within/df within

To calculate F-ratio:
MS between/MS within

After filling in the table and finding the F-ratio, find the critical or cutoff value to reject the null using an F-table at .05 level of significance. Compare to the F-ratio to determine whether or not to reject the null. If the null is rejected, there is a difference. If the null is not rejected, there is no difference.

Use the Tukey procedure to compare all possible pairs of means to determine which differs.

I hope this brief summary will help get you started.