Question

Chap 13 Susan Sound wants to know if constant background sound, as opposed to an unpredictable sound or no sound at all, effects how students learn. She randomly divides twenty-four students into 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 test over the material. Their scores are as follows: group test scores 1) constant sound 2) random sound 3) no sound 7 4686629 55344722 2 4712155 Use a 0.05 significance level to test the claim that the different background sounds while studying have no effect on students test scores. a. State the null and alternative hypothesis symbolically and in words. b. Find the P-value c. State the statistical conclusion. d. Write the conclusion sentence

Answer 1

(a) Null and alternative hypothesis symbolically: Ho: HH2 3 H4 Not all the means are equal Null and alternative hypothesis symbolically in words: Ho: The different background sound while studying has no effect on students test score Ha The different background sound while studying has effect on students test score Anova: Single Factor SUMMARY Groups Count Sum Average Variance Constant sound 8 48 6 4.8571 random sound 8 32 2.8571 27 3.375 4.8393 no sound ANOVA Source of Variation Between Groups Within Groups df P-value F crit SS MS F 30.0833 2 15.0417 3.5946 0.0454 3.4668 87.8750 21 4.1845 Total 117.9583 23 b)p-value 0.0454 c) The statistical conclusion: The p-value of F test is less than 0.05. Hence we reject null hypothesis at 5% level of significance d) Conclusion Since null hypothesis is rejected. Hence we conclude that the different background sound while studying has effect on students test score 00