A researcher studied the effect of television violence on concentration of a particular blood chemical. In this study, 40 participants were measured over a period of an hour prior to watching a violent show and then immediately after. In the results section, the researcher writes: "There was a significant decline in blood concentration from a mean of 13.41 (SD=2.48) to 12.38 (SD=2.69), t(39)=3.38, p<.01 (one tailed)."
Can you explain this result (including the underlying logic of the computations) to me who understands hypothesis testing involving a single sample and a known population, but knows nothing about t tests?
Please find the formatted solution of your posting in the attached file. I hope it will help you to understand the topic. Thanks!
Here we have two samples such as
Prior watching a violent show and after watching a violent show
(*Example of how to arrange the data is found in the ...
This solution is comprised of a detailed explanation for the results of t test. Full description is given including mean and standard deviation, level of significance, t test statistics value, P-value, decision about rejecting or not rejecting the null hypothesis along with concluding remarks are given in the solution.