PLEASE SHOW ALL FORMULAS AND ALL WORK BY HAND

1.Below are the data from a study examining the effects of exercise on stress. After measuring stress levels in 5 students, they were placed on an exercise program for two weeks. Then their stress levels were measured again. The data are shown as the level of stress.

Pre-Exercise Stress LevelPost-Exercise Stress Level

8 5

7 3

8 3

9 5

8 4

(a) What are the independent (IV) and dependent variables (DV) in this study? (2 pts)

(b) What kind of variable is the dependent variable?

(c) For BOTH groups, calculate the mean, median and mode.

(d)Which of these measures of central tendency best reflects the distribution for each group?Why?

(e) What is the experimental design for this study?

2. Using the measure of central tendency that you chose in the previous answer (1d) draw an appropriate graph comparing the pre- and post-exercise conditions.Label the graph completely.Explain why you chose this type of graph.What conclusions can you make from a visual inspection of the data in the graph?

3. Using the data for the Pre-Exercise Condition ONLY from problem #1, calculate the range, variance, and standard deviation. Clearly identify each.

4. Mary received the following grades in four of her classes.Show all of your work and explain your answers.

SubjectMary's GradeClass MeanClass Stand. Dev.

Psychology82802

Math43446

History20220010

English68645

(a) What was Mary's best subject?Why?

(b) What was Mary's worst subject?Why?

(c) What was Mary's percentile ranking in her Psychology class?

(d) For her History class, what percentage of students had scores between 195 and 205?