In this section, we saw a relationship between armspans and height. There are other linear relationships between body measurements. One such relationship is between the circumference of a wrist and the circumference of a neck. Wrap your hand around your wrist to get a sense of the circumference. The distance around your wrist is approximately the same as the circumference of the circle created with your thumb and middle finger. Now take your hands and wrap them around your neck. For many people, the circumference of their neck is approximately twice the3 circumference of their wrist.
The following table lists wrist and neck circumferences for a group of college students.
|
Wrist Circumference (in.)
|
5.5
|
6
|
6
|
6.5
|
7
|
7
|
7.5
|
8
|
8.5
|
9
|
|
Neck Circumference (in.)
|
10
|
13
|
12.5
|
12
|
13.5
|
14
|
14
|
13
|
18
|
21
|
A.) Use this data to create a scatterplot. Graph neck circumference versus wrist circumference.
B.) Graph the trendline NC= 2.4WC-2.8 on the scatterplot. NC. Represents neck circumference and WC represents wrist circumference. The trendline equation illustrates that neck circumference. Is approximately twice wrist circumference.
C.) Use the equation of the trendline to estimate the neck circumference in inches for someone whose wrist circumference is 6.25 inches.
D.) Find the residual for the predicted neck circumference from part c if the actual neck circumference is 12.5 inches. Interpret the value.