Question

A researcher hypothesizes that reaction time (RT) measured in milliseconds in response to a startling stimulus will be lower (faster) before people drink 5 beers than it will be afterward. A sample of 12 patients is presented with a startling stimulus, and their mean score is 6.08 milliseconds with an SD of 1.38. They drink 5 beers, another startling stimulus is presented, and participants’ mean reaction time is 14.25 milliseconds with an SD of 3.7. The raw scores and Z-scores were as follows:

RT before: 7 8 7 8 5 6 6 5 3 6 6 6

Z before: 0.97,1.79,0.97,1.79,-0.69, 0.14, 0.14, -0.69, -2.34, 0.14,0.14,0.14

RT after: 16,19,15,15,14,15,13,12,4,15,16,17

Z after: 0.49,1.34,0.21,0.21,-0.07,0.21,-0.35,-0.64,-2.90,0.21,0.49,0.78

Test the researcher’s hypothesis at α = .05.

state which statistical test you should use, (e.g., single-sample t- test, paired-samples t- test etc.) Show the value of the obtained inferential statistic (e.g.,t= 2.17), the degrees of freedom

and the critical value from the relevant table, and state whether you should reject or accept the null hypothesis ,Calculate effect size when applicable.Then explain, in non-statistical language

(completely in layperson’s terms) what the practical conclusion of your analysis is, including the direction of the effect.

Answer 1