Pelton (1983) has shown that Olympic marksmen shoot much better if they fire between heartbeats, rather than squeezing the trigger during a heartbeat. The small vibration caused by a heartbeat seems to be sufficient to affect the marksman’s aim. Olympic marksmen fire a series of rounds while a researcher records heartbeats. For each marksman, a score is recorded for shots fired during heartbeats and for shots fired between heartbeats.
Answer the following questions.
1. Focus on the Descriptive Statistics output. Compare the means for the two conditions. Remember that the marksmen were measured twice, when they shot during heartbeats and when they shot between heartbeats. At which time, during or between, did they score more points?
2. Focus on the Paired Samples T-Test output. a. What is the value for t? b. What is p? p is the exact alpha that corresponds to the value for t. c. Should the researcher reject or retain the null hypothesis? d. Note that a paired-samples t-test is the same thing as a repeated- measures t-test.
3. If there’s a difference in shots taken during and between heartbeats, you should expect to see a significant difference between the two conditions. According to the findings reported in the output above, was there a significant difference between the scores for the marksmen during and between heartbeats?