The following data set records the cost of advertising (in thousands of dollars) and the number of products sold (in thousands).
|
Cost (x)
|
9
|
2
|
3
|
4
|
2
|
5
|
9
|
10
|
|
Number (y)
|
85
|
52
|
55
|
68
|
67
|
86
|
83
|
73
|
Using Minitab, find or create each of the following.
a. The value of r and the equation of the line of best fit.
b. A scatter-plot for the data set. Based on the value of r you calculated above and this scatter-plot, do you believe the line of best fit will provide a reliable prediction for the number of products sold based on the cost of advertising? Why or why not?
c. What is the best prediction for the number of products sold based on advertising costs of $7000?