## Relationship between systolic blood pressure and weight:

Part 1

The following scatterplot shows the relationship between systolic blood pressure and

weight:

1

Which of the following could describe what is shown in the figure?

A. r = -0.406, y = 95.34 – 0.32X

B. r = -0.406, y = 95.34 + 0.32X

C. r = -0.406, y = -95.34 – 0.32X

D. r = -0.406, y = -95.34 + 0.32X

E. r = 0.406, y = 95.34 – 0.32X

F. r = 0.406, y = 95.34 + 0.32X

G. r = 0.406, y = -95.34 – 0.32X

H. r = 0.406, y = -95.34 + 0.32X

Part 2: Part 2

2

For which of the following is there no linear relationship?

A. y = 0 + 3X

B. 0 = 1 + 3X

C. y = 3 + 0X

D. y = 0 – 3X

Part 3: Part 3

313 patients in a local clinic participated in a study to examine whether Standing Height

(cm) explains variation in systolic blood pressure (1st reading) mm Hg.

Here is some output obtained when a bivariate regression analysis was performed:

3

Accepted characters: Only numbers, decimal point markers (i.e., periods), or sign

indicators preceding a number (e.g., -5) are allowed, except where scientific

notation is needed. Values in scientific notation format should use “e” to

represent “times 10 to the power of” (e.g., 3e-3 means 3 x 10-3).

What is the proportion of variance (in percent) explained in Systolic Blood

Pressure (1st reading) mm Hg by Standing Height (cm)? ____ %

4

Is there a statistically significant linear relationship between Standing Height (cm)

and Systolic Blood Pressure (1st reading) mm Hg?

A. No

B. Yes

5

Explain how you arrived at your answer to question 4 above. Clearly identify

which test and what sig was used to arrive at your conclusion.

6

Accepted characters: Only numbers, decimal point markers (i.e., periods), or sign

indicators preceding a number (e.g., -5) are allowed, except where scientific

notation is needed. Values in scientific notation format should use “e” to

represent “times 10 to the power of” (e.g., 3e-3 means 3 x 10-3).

How many standard deviation does Systolic Blood Pressure (1st reading) mm Hg

change for a 1 standard deviation change in Standing Height (cm)? ____

7

Accepted characters: Only numbers, decimal point markers (i.e., periods), or sign

indicators preceding a number (e.g., -5) are allowed, except where scientific

notation is needed. Values in scientific notation format should use “e” to

represent “times 10 to the power of” (e.g., 3e-3 means 3 x 10-3).

How many units does Systolic Blood Pressure (1st reading) mm Hg change for a 1

unit change in Standing Height (cm)? ____

8

Write the regression equation for predicting Systolic Blood Pressure (1st reading)

from Standing Height (cm). Your regression formula should be in the form of Y =

B0 + B1*X.

9

Accepted characters: Only numbers, decimal point markers (i.e., periods), or sign

indicators preceding a number (e.g., -5) are allowed, except where scientific

notation is needed. Values in scientific notation format should use “e” to

represent “times 10 to the power of” (e.g., 3e-3 means 3 x 10-3).

What is the predicted Systolic Blood Pressure (1st reading) mm Hg for a patient

with 160 in Standing Height (cm)? Keep three decimal places in your calculation

and final answer. ____

Part 4: Part 4

At a local clinic, the patients were recruited to analyze the effects of various variables in

explaining Systolic Blood Pressure (1st reading) mm Hg. Some of the variables included in

this study are Standing Height (cm), Weight (kg), Total Cholesterol (mg/dL), and Fasting

Glucose (mg/dL). A multiple regression was conducted to determine the extent to which

Systolic Blood Pressure (1st reading) mm Hg can be explained by these variables. Here is

the output obtained when a multiple regression analysis was performed, with all of the

variables entered simultaneously:

10

Is the overall model statistically significant?

A. No

B. Yes

11

Explain how you arrived at your answer to question 10 above. Clearly identify

which test and what sig was used to compare to what value in order to arrive at

your conclusion.

12

Accepted characters: Only numbers, decimal point markers (i.e., periods), or sign

indicators preceding a number (e.g., -5) are allowed, except where scientific

notation is needed. Values in scientific notation format should use “e” to

represent “times 10 to the power of” (e.g., 3e-3 means 3 x 10-3).

How many patients were in this study? ____

13

Accepted characters: Only numbers, decimal point markers (i.e., periods), or sign

indicators preceding a number (e.g., -5) are allowed, except where scientific

notation is needed. Values in scientific notation format should use “e” to

represent “times 10 to the power of” (e.g., 3e-3 means 3 x 10-3).

How many independent variables were included in the model? ____

14

Accepted characters: Only numbers, decimal point markers (i.e., periods), or sign

indicators preceding a number (e.g., -5) are allowed, except where scientific

notation is needed. Values in scientific notation format should use “e” to

represent “times 10 to the power of” (e.g., 3e-3 means 3 x 10-3).

What is the proportion of variance (in percent) explained in Systolic Blood

Pressure (1st reading) mm Hg by the independent variables? ____ %

15

Which independent variable explains the least amount of variance in Systolic

Blood Pressure (1st reading) mm Hg?

A. Standing Height (cm)

B. Weight (kg)

C. Total Cholesterol (mg/dL)

D. Fasting Glucose (mg/dL)

16

How did you determine the answer to question 15 above? Please specify what

value you used and what it was compared to for you to arrive at your conclusion.

17

Which independent variable explains the most amount of variance in Systolic

Blood Pressure (1st reading) mm Hg?

A. Standing Height (cm)

B. Weight (kg)

C. Total Cholesterol (mg/dL)

D. Fasting Glucose (mg/dL)

18

How did you determine the answer to question 17 above? Please specify what

value you used and what it was compared to for you to arrive at your conclusion.

19

Which of the following independent variable is/are statistically significant? Select

all that apply.

A. Standing Height (cm)

B. Weight (kg)

C. Total Cholesterol (mg/dL)

D. Fasting Glucose (mg/dL)

20

We wish to add to the model the variable marital status (1=married, 2=widowed,

3=divorced, 4=separated, 5=living with partner, 6=never married). Describe how

we can include this in the model.

21

If we want to see whether the effects of Weight (kg) on Systolic Blood Pressure

(1st reading) mm Hg differed for males (Gender = 1) and females (Gender = 0),

what do we need to do to test this effect?