If a researcher was planning a randomized controlled trial to evaluate the effect of an exercise intervention (intervention group vs. control group) on blood pressure, in which situation would you need a larger sample size to achieve the same level of power.  Assume all other factors are kept the same.

Power can range from -1 to +1.

A researcher was interested in comparing 3 group conditions: Meditation, Progressive Muscle Relaxation PMR), and a Control condition on heart rate. 28 freshmen undergraduates from USF were randomly selected.  From these 28 students, 13 were randomized to the Control Condition, 8 were randomly assigned to Meditation, and 7 were randomly assigned to Progressive Muscle Relaxation. Using a .05 level of significance is there a statistically significant difference between PMR and Meditation?

When researchers discuss statistical interaction, what type of variable are researchers focusing on?

A researcher examined the body mass index (BMI) of 1000 randomly selected undergraduates from USF and found a mean of 25. If the median BMI was 18, what would you conclude about the shape of the distribution of BMI scores?

A researcher was interested in evaluating an intervention that would impact body mass. The researcher was also interested in evaluating if there were sex differences in body mass. The researcher recruited 10 males and 10 females for the study. For the 10 males, 5 males were randomly assigned to the intervention and 5 males were randomly assigned to a control condition. Similarly, for the 10 females, 5 females were randomly assigned to the intervention and 5 females were randomly assigned to a control condition. How many Main Effects are there in this design (statistically significant or not statistically significant)?

Using the correlation matrix below, what is the correlation between CMJump and Squad bin?

A researcher measured body mass (BM) for 100 undergraduates. The mean BM was 20 (SD=4). What would a person’s z-score be if the person had a body mass of 12?

Extra Credit – No Penalty for Trying Suppose a researcher compares 4 groups (Freshmen, Sophomores, Juniors, Seniors) on the average number of steps taken per day, and finds an overall significant F-ratio. What is the logic of using post hoc methods like the Tukey method or Bonferroni method in making pairwise comparisons (why are these special methods needed)?

A researcher was interested in comparing 3 group conditions: Meditation, Progressive Relaxation, and a Control condition on heart rate. 28 freshmen undergraduates from USF were randomly selected.  From these 28 students, 13 were randomized to the Control Condition, 8 were randomly assigned to Meditation, and 7 were randomly assigned to Progressive Relaxation. What would be the degrees of freedom for: Between groups df = _____