Question

2. A sample of n = 16 difference scores from a repeated measures experiment has SS = 440. The average difference score is 3. For a two-tailed test, α = .05, is this a significant difference?

3. At the Olympic level of competition, even the smallest factors can make the difference between winning and losing. For example, research shows that Olympic marksmen shoot much better if they fire between heartbeats, rather than squeezing the trigger during a heartbeat. The small vibration caused by the heartbeat is sufficient to affect the marksman’s aim. A sample of n = 6 Olympic marksmen fired a series of rounds while a researcher recorded heartbeats. For each marksman, a score is recorded for shots fired during heartbeats and for shots fired between heartbeats. Do these data indicate a significant difference? Test with α = .05 and a two tailed test. (SS = 34.83, s² = 6.97).

                              During                    Between

Subject               Heartbeat               Heartbeats

     A                          93                              98

     B                          90                              94

     C                          95                              96

     D                          92                              91

     E                          95                               97

     F                          91                               97

Answer 1