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Lab #8 – Scatter Plots and Correlation
SOLUTION
Due Friday, April 11, 2008 at the beginning of class
For this lab we will use two data sets.
The data sets are available in the accompanying Excel Workbook.
Fitness
The first data set is on the worksheet titled “Fitness”.
This data set gives measurements made on
men involved in a phyical fitness course at N.C. State University (and taken from the SAS
documentation).
The variables are:
•
Age (in years)
•
Weight (in kilograms)
•
Oxygen Intake Rate (in ml per kg body weight per minute)
•
Time to Run 1.5 miles (in minutes)
•
Heart Rate (pulse) while Resting
•
Heart Rate (pulse) while Running (taken at the same time Oxygen rate was measured)
•
Maximum heart rate recorded while running
Children
The second data set is on the worksheet titled “Children”.
The data set is from Lewis and Taylor,
1967 ( and taken from the SAS documentation.)
The variables are:
•
Age (in months)
•
Height (in inches)
•
Weight (in pounds)
1.
For the following questions, use the “Fitness” data set.
a.
Make a nice table giving the Pearson Correlation Coefficients for all pairs of variables in this data
set.
Use SAS to get the correlations, but do not paste SAS output here.
Age
Weight
Oxygen
Intake
Run
Time
Resting
Pulse
Running
Pulse
Max.
Pulse
Age
1.000
.234
.305
0.189
.164
.338
.433
Weight
1.000
.163
0.144
0.044
0.182
0.249
Oxygen Intake
1.000
.862
.399
.398
.237
Run Time
1.000
0.450
0.314
0.226
Resting Pulse
1.000
0.352
0.305
Running Pulse
1.000
0.930
Max. Pulse
1.000
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View Full Document b.
Using Excel, make a
nice
scatter plot of the maximum heart rate (on the
y
axis) against the heart
rate while running (on the
x
axis).
Give the plot and give the Pearson Correlation coefficient for
these two variables.
The Pearson Correlation Coefficient between Maximum Pulse and Running Pulse is 0.92975
.
(no credit for giving r
2
)
150
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Running Pulse
Maximum Pulse
c.
Using Excel, make a
nice
1
scatter plot of the weight(on the
y
axis) against the age (on the
x
axis).
Give the plot and give the Pearson Correlation coefficient for these two variables.
The Pearson Correlation Coefficient between Age and Weight is 0.23354
(no credit for giving r
2
)
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Age
Weight (kg)
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View Full Document 2.
For the following questions, use the “Children” data set.
a.
Using SAS, find the correlation between height and age for boys.
0.74656
b.
Using SAS, find the correlation between height and age for girls.
0.54385
c.
Using SAS, plot height (on
y
axis) against age (on
x
axis) for all children.
Use the child’s gender
as the points on the plot.
(That is, the points for girls would be “f” and the points for boys would
be “m”.)
Plot of height*age.
Symbol is value of sex.
height ‚
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This note was uploaded on 03/09/2010 for the course STAT 350 taught by Professor Staff during the Spring '08 term at Purdue University.
 Spring '08
 Staff
 Statistics, Correlation, Scatter Plots

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