Question 1

A correlation coefficient must lie between

Group of answer choices

0 and 1

-1 and 0

-1 and 1

None of above

Question 2

A correlation coefficient between the variables x and y is - 0.7. It indicates

Group of answer choices

as x increase, y tends to increase.

as x increase, y tends to decrease.

as x decrease, y tends decrease

Can not be determined

Question 3

A correlation coefficient between the variables x and y is 0.8. It indicates

Group of answer choices

as x increase, y tends to increase.

as x increase, y tends to decrease.

as x decrease, y tends increase.

Can not be determined

Question 4

There are two correlation coefficients. One is 0.8, and the other 0.5. The strong correlation coefficient is

Group of answer choices

0.8

0.5

Can not be determined.

Question 5

There are two correlation coefficients. One is - 0.8, and the other 0.5. The strong correlation coefficient is

Group of answer choices

- 0.8

0.5

Can not be determined.

Question 6

There are two correlation coefficients. One is - 0.8, and the other -0.5. The strong correlation coefficient is

Group of answer choices

- 0.8

- 0.5

Can not be determined.

Question 7

The Pearson correlation coefficient between two variables x and y requires

Group of answer choices

x follows normal distribution, and y can be any distribution

y follows normal distribution, and x can be any distribution

both x and y follow normal distribution

Question 8

A regression equation of infant weight (oz) and age (day) from 20 infants who had age from 0 to 5 days is y= 113.3 + 2.16*age. Based on this regression equation, please answer following questions 8 to 14. ___________________________________________________________________ The predicted birth weight is

Group of answer choices

119.8 oz

113.3 oz

115.5 oz

Can not be determined

Question 9

The predicted infant weight age day 1 is

Group of answer choices

119.8 oz

113.3 oz

115.5 oz

Can not be determined

Question 10

The predicted infant weight age day 3 is

Group of answer choices

119.8 oz

113.3 oz

115.5 oz

Can not be determined

Question 11

In this regression equation, infant weight is

Group of answer choices

Independent variable

Dependent variable

Neither independent variable, nor dependent variable

Question 12

In this regression equation, age is

Group of answer choices

Independent variable

Dependent variable

Neither independent variable, nor dependent variable

Question 13

In this regression equation, the intercept is

Group of answer choices

2.16 oz

113.3 oz

115.5 oz

Can not be determined

Question 14

In this regression equation, the slope coefficient is

Group of answer choices

2.16 oz

113.3 oz

115.5 oz

Can not be determined

ion of quality of life scale (0-100, 100 is best) associated with Age (year), Income (unit US $), CD4 count from 695 Africa HIV infected women is The quality of life scale = 32.121 + 0.060 * Income + 0.017 * CD4 count - 0.045 * Age. Based on this regression equation, please answer following questions 15 to 29. ____________________________________________________________________ Given an Africa HIV infected woman with an income $200, CD4 250 and age 40, the predicted quality of life scale is

Group of answer choices

32.121

46.571

34.571

Can not be determined

Question 16

Given an Africa HIV infected woman with an income $100 and CD4 200, the predicted quality of life scale is

Group of answer choices

32.121

46.571

34.571

Can not be determined

Question 17

In this multiple regression equation, the intercept is

Group of answer choices

32.121

46.571

34.571

Can not be determined

Question 18

Given an Africa HIV infected woman with no income, CD4 250 and age 40, the predicted quality of life scale is

Group of answer choices

32.121

46.571

34.571

Can not be determined

Question 19

In this multiple regression equation, the quality of life scale is

Group of answer choices

Independent variable

Dependent variable

Neither independent variable, nor dependent variable

Question 20

In this multiple regression equation, the income is

Group of answer choices

Independent variable

Dependent variable

Neither independent variable, nor dependent variable

Question 21

In this multiple regression equation, the CD4 count is

Group of answer choices

Independent variable

Dependent variable

Neither independent variable, nor dependent variable

Question 22

In this multiple regression equation, the age is

Group of answer choices

Independent variable

Dependent variable

Neither independent variable, nor dependent variable

Question 23

The difference of predicted quality of life scale between the woman with an income $200, CD4 250 and age 40 and the woman with no income, CD4 250 and age 40 is

Group of answer choices

0.450

12.000

1.7

6.000

Question 24

The difference of predicted quality of life scale between the woman with an income $200, CD4 250 and age 40 and the woman with an income $100, CD4 250 and age 40 is

Group of answer choices

0.450

12.000

1.7

6.000

Question 25

The difference of predicted quality of life scale between two women with same income and same CD4 count, but one age 30 and the other 40, is

Group of answer choices

0.450

12.000

1.7

6.000

Question 26

The difference of predicted quality of life scale between two women with same income and same age, but one CD4 count 200 and the other 100, is

Group of answer choices

0.450

12.000

1.7

6.000

Question 27

As income increases one dollar, the predicted quality of life scale increases

Group of answer choices

32.121

0.060

0.017

-0.045

Question 28

As CD4 count increases one count, the predicted quality of life scale increases

Group of answer choices

32.121

0.060

0.017

-0.045

Question 29

As age increases one year, the predicted quality of life scale increases

Group of answer choices

32.121

0.060

0.017

-0.045