dsrt week 14

DSRT 734 M51

INFERENTIAL STATISTICS FOR DECISION MAKING

Week-14 Discussions, Questions, and Problems

Chapter 15

After reading your textbook, I want you to have a good understanding of the fundamentals of each chapter and show it to me. Please don’t copy & paste from your textbook or some other online source. In other words, don’t plagiarize. You can read online material but you have to write your own sentences.

1. Explain why nonparametric tests are used rather than a t test or an ANOVA

2. The scores below are ranks. They were obtained by taking each raw score and giving it a rank of 1 to 4.

Group 1 Group 2

1 3

2 4

What would be the most likely analysis described above?

3. What rank would a score of 4 have in the following sampling distribution?

1, 2, 3, 3, 3, 4, 4, 4, 6

Explain your answer and show your work.

Chapter-15

1. Students in a 1 P.M. laboratory section in general psychology observed eight people they did not know and made a judgment about their IQ. Half the eight wore glasses; half did not. The 3 P.M. laboratory section judged the same eight persons, but those who wore glasses at 1 P.M. did not wear them at 3 P.M. and vice versa. The result was that each of the eight was given an estimated IQ both with and without glasses. What is the question this experiment is designed to answer? What is the answer to the question? Show all of your work.

Without Glasses	With Glasses
121	127
97	104
114	110
131	139
118	120
91	86
127	140
114	125

2. a. An aerobics teacher believed that physical conditioning is an important factor in the ability to perform skills, even if the skill does not require strength or endurance. To test this hypothesis, she selected 10 high BMI (body mass index) women enrolled in her aerobics course. Before the first class, she tested them on a button-sorting task. After a full semester of regular exercise, she tested the women on the same button-sorting task. Scores represent the number of seconds required to sort the buttons. Analyze the data with a nonparametric test and comment on the aerobics teacher's hypothesis.

Subject Pretest Score Posttest Score

1 29 31

2 33 28

3 36 39

4 37 37

5 40 44

6 42 41

7 45 51

8 47 50

9 50 56

10 56 49

b. What is the correlation between the pretest and posttest rankings of the women on the button-sorting test? Find the correlation and explain what it means.