Refer to given Exercise and the table for Exercise in which heights and mid-parent heights are given for 18 college students (Data source: UCDchap3 dataset on the website for this book).
Draw a scatterplot for the data, using different symbols for males and females as instructed in part (b) of Exercise. Based on the scatterplot, would you say that the correlation between height and mid-parent height is higher for the females in the sample or for the males? Or are the correlation values about the same for males and females? Explain your reasoning.
Exercise
The following table shows sex, height (inches), and mid parent height (inches) for a sample of 18 college students. The variable mid-parent height is the average of mother's height and father's height. (These data are in the dataset UCDchap3 on the companion website; they are sampled from the larger dataset UCDavis2.)
|
Sex, Height and Mid-Parent Height for 18 college students
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|
Sex
|
Height
|
Mid-Parent Height
|
|
M
|
71
|
64.0
|
|
F
|
60
|
63.5
|
|
F
|
66
|
67.0
|
|
M
|
70
|
64.5
|
|
F
|
65
|
65.5
|
|
F
|
66
|
69.5
|
|
M
|
74
|
72.5
|
|
F
|
67
|
67.5
|
|
F
|
63
|
65.5
|
|
M
|
67
|
64.0
|
|
F
|
69
|
70.0
|
|
M
|
65
|
63.0
|
|
M
|
72
|
69.0
|
|
M
|
68
|
67.0
|
|
F
|
63
|
63.0
|
|
F
|
61
|
63.0
|
|
M
|
74
|
69.5
|
|
F
|
65
|
67.5
|
a. In the relationship between height and mid-parent height, which variable is the response variable (y) and which is the explanatory variable (x)?
b. Draw a scatterplot of the data for the y and x variables defined in part (a). Use different symbols for males and females.
c. Briefly interpret the scatterplot. Does the association appear to be linear? What are the differences between the males and females? Which points, if any, are outliers?
d. Calculate the difference between height and mid-parent height for each student, and draw a scatterplot of y = difference versus x = mid-parent height. Use different symbols for males and females. What does this graph reveal about the connection between height and midparent height?