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:
Low Volume Moderate Volume High Volume
X 61.5 65.5 48.25
n 4 5 7
Source Sum of Squares df Mean Square F
Between groups 652.16 _____ _____ _____
Within groups 612.75 _____ _____
Total 1264.92 _____
(a) Complete the ANOVA.
(b) At _ 5 .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.