## Question 970:

Suppose you wish to test the effect of a new medication (X) compared to Prozac on the well-being of depressed individuals, using a standardized "well-being scale" that sums Likert-type items to obtain a score that could range from 0 to 20. Higher scores indicate greater well-being (that is, the medication is having a positive effect). The well-being scale score was assessed for 8 patients before and after they received Prozac. The well-being scale score were taken for other new 8 patients before and after they received the treatment “X”. The well-being scale scores for both treatments are shown below:Treatment

Prozac

New treatment (X)

Before Prozac

After Prozac

Change in score

(After-Before)

Before New treatment (X)

After New treatment (X)

Change in score

(After-Before)

5

3

2

11

18

7

8

9

1

8

7

-1

1

0

-1

12

17

5

5

11

6

15

18

3

7

17

10

14

14

0

3

2

-1

9

17

8

5

9

4

14

14

0

8

8

0

11

15

4

Treatment

Prozac

New treatment (X)

Before Prozac

After Prozac

Change in score

(After-Before)

Before New treatment (X)

After New treatment (X)

Change in score

(After-Before)

Mean

SD

Proportion of subjects with improved well-being after treatment

QWhat is the mean change in the well-being scale score for patients who were assigned to Prozac? Calculate the 95% confidence interval for the mean change.

QCan we conclude that “Prozac improves the well-being significantly” since it increased the well-being scale score for patients who were assigned to Prozac?

QOn average, the well-being scale score increased by 1 unit for patients who received Prozac and by 4 units for patients who received new treatment (X). What is mean difference between the two means (i.e the difference in the change of well-being score between the two treatments)

QWhat is the pooled variance for well-being score for the two treatment groups?

QWhat is the standard error for the difference between the two means?

QOn average, the well-being scale score increased by XXX unit for patients who received Prozac and by XXX units for patients who received new treatment (X). What is the 95% confidence interval for the difference between the two means (i.e the difference in the change of well-being score between the two treatmnents)

QCan we conclude that there is significant difference between the two treatments in improving the well-being?

QWhat is the proportion (and its 95% confidence interval) of patients whose well-being score increased after taking Prozac?

QWhat is the 95% confidence interval of the difference in the proportions of patients whose well-being score increased between the two treatments?

Q Is there significant difference in the proportions of patients whose well-being score increased between the two treatments?

QConfidence intervals around a mean value gives you a range within which the _____ mean is likely to fall.

Q A population has a mean of 166 and a standard deviation of 30. A random sample of 100 from this population is selected. The sample has a mean of 160 and a standard deviation of 33. The sampling error is

PUT ANYNUMBER INSTEAD OF X OR XX OR XXX .....ETC

THNKS A LOT