Question

In the college population, the mean reading comprehension test score is μ = 75 and σ = 25. A researcher wanted to investigate the effect of listening to hip-hop music on reading comprehension. She randomly selected a sample of n = 100 college students. The sample of students completed a reading comprehension test while hip-hop music was played in the background the sample mean reading comprehension score was M = 68. Do the data indicate a significant effect of hip-hop music on reading comprehension? Use a two-tailed z - test with p < .05 to answer this research question.

- Null and alternative hypotheses - All computational steps of the z-test - Critical z-value used for decision about H0

- Decision about H0 (i.e., reject or fail to reject) - If the effect is significant, compute the Cohen's d to establish the size of the effect

- is the effect small, medium or large?

- Conclusion in APA style: interpretation of the z-test outcome to answer the research question. Is there a significant effect of hip-hop music on reading comprehension or not? If there is a significant effect, address in your conclusion the direction of the effect (i.e., is the effect positive or negative/is there an improvement or decline of reading comprehension?) and report the Cohen's effect size.

Answer 1

The Cohen's d effect size is

It is medium effect size.

The result in APA style is

z = -2.80, p < 0.05

Is there a significant effect of hip-hop music on reading comprehension or not? yes

If there is a significant effect, address in your conclusion the direction of the effect (i.e., is the effect positive or negative/is there an improvement or decline of reading comprehension?)

Since test statistics is negative so effect size is negative. There is a decline of reading comprehension.

The Cohen's effect size is 0.28. It is medium effect size.