Sam collected data in problem 7-5 by sharpening her pencil and comparing the length
of the painted part of the pencil to its weight. Her data is listed in the table below.
Length of paint (cm) 13.7 12.6 10.7 9.8 9.3 8.5 7.2 6.3 5.2 4.5 3.8
Weight (g)
4.7 4.3 4.1 3.8 3.6 3.4 3.0 2.8 2.7 2.3 2.3
Graph the data on your calculator and sketch the graph on your paper.
What is the equation of the LSRL? Sketch it on your scatterplot.
Create a residual plot and sketch it on your paper.
Interpret your residual plot. Does it seem appropriate to use a linear model to
make predictions about the weight of a pencil?
a.
b.
C.
d.
e.
Sam's pencil, when it was new, had 16.75cm of paint and weighed 6g. What
was the residual? What does a positive residual mean in this context?