Reconsider the previous exercises on handedness and reaction time. If you haven’t already done so, put the data file Reaction Times into the Matched Pairs applet and do at least 1,000 randomizations.

a. Determine an approximate 95% confidence interval using the 2SD rule for the mean difference in the reaction times (dominant − nondominant).
b. Explain what your confidence interval from part (a) means. In other words, we are 95% confident of what?
c. Based on your confidence interval is there strong evidence that using the nondominant hand results in slower average reaction times? Explain why or why not.

Data from previous exercise

Student researchers wanted to see if a person’s reaction time is slower if they use their nondominant hand to click a computer mouse compared to using their dominant hand. The researchers had a computer program that would display a red circle. When it changed to yellow, the subjects were to click the mouse as fast as they could and the computer would calculate the reaction time. Researchers had their subjects find their reaction time with their dominant hand (e.g., right hand for right handers) and also with their nondominant hand. Th ey randomly determined which hand was tested first. The reaction times (in seconds) for the subjects for each condition can be found in the data file Reaction Times.