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?
Sample Solution
