questions 4 and 6 Need answer for #4 and #6.. #5 is a reference

 

 

#4What measure of effect size is used for a

correlated-groups t test?

5. A researcher is interested in whether participating

in sports positively influences selfesteem

in young girls. She identifies a group

of girls who have not played sports before

but are now planning to begin participating

in organized sports. She gives them a

50-item self-esteem inventory before they

begin playing sports and administers it

again after six months of playing sports.

The self-esteem inventory is measured on an

interval scale, with higher numbers indicating

higher self-esteem. In addition, scores on

the inventory are normally distributed. The

scores appear below.

Before After

44 46

40 41

39 41

46 47

42 43

43 45

a. What statistical test should be used to

analyze these data?

b. Identify H0 and Ha for this study.

c. Conduct the appropriate analysis.

d. Should H0 be rejected? What should the

researcher conclude?

e. If significant, compute the effect size and

interpret.

f. If significant, draw a graph representing

the data.

6. The student in Question 5 from Module 18

decides to conduct the same study using a

within-subjects design in order to control

for differences in cognitive ability. He selects

a random sample of participants and

has them study different material of equal

difficulty in both the music and no music

conditions. The data appear below. As

before, they are measured on an intervalratio

scale and are normally distributed.

Music No Music

6 10

7 7

6 8

5 7

6 7

8 9

8 8

a. What statistical test should be used to

analyze these data?

b. Identify H0 and Ha for this study.

c. Conduct the appropriate analysis.

d. Should H0 be rejected? What should the

researcher conclude?

e. If significant, compute the effect size and

interpret.

f. If significant, draw a graph representing

the data.