A researcher forecasts that students will learn differently depending upon whether there is a constant background sound, an unpredictable sound or no sound at all. She randomly separates twenty---four students in three groups of eight. All students study a passage of text for 30 minutes. Those in group 1 study with background sound at a constant volume in the background. Those in group 2 study with noise that changes volume periodically. Those in group 3 study with no sound at all. After studying, all students take a 10 point multiple choice tests about the material they read. The tests were graded from 0---10. The mean score for the constant sound group was 6, for unpredictable sound were 4, and for no sound were 3.375. She then calculated the SSB to be 30.08 and the SSW to be 87.88.
Conduct hypothesis test to find out if type of sound has effect on learning ability. Employ a significance level of 5%.
Also if the null hypothesis is rejected and the researcher wanted to continue on to conduct pair wise comparisons, to find out which group(s) was different from the others. What significance level would need to be employed for each pair wise comparison, in order to uphold an entire significance level of 5%?
What technique would be employed for making the pair wise comparisons?