The numbers (in thousands) of vehicle-train collisions and in- juries are shown in Table 15 for various years.

Let I be the number (in thousands) of injuries from vehicle- train collisions in a year when there were C collisions (in thou- sands).
a. For the association between C and I, identify the explanatory and response variables.
b. Construct a scatterplot by hand that describes the association between C and I.
c. Is the association positive, negative, or neither? What does that mean in this situation? Why does this make sense?
d. Graph the model I = 0.36 C + 0.10 by hand on the scatterplot. Does the model come close to the data points?
e. Use the model to predict the number of injuries in a year when there were 5 thousand vehicle-train collisions.

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Table 15 Numbers of Vehicle-Train Collisions and Injuries Number of Collisions (thousands) 9.5 7.1 5.7 4.6 3.5 3.1 2.1 2.3 Number of Injuries thousands 3.3 2.7 2.4 1.9 1.2 Year 1981 1985 1990 1995 2000 2010 2014 0.9 0.8