Dave Fletcher, the general manager of North Carolina Engineering Corporation (NCEC), thinks that his firm's engineering services contracted to highway construction firms are directly related to the volume of highway construction business contracted with companies in his geographic area. He wonders if this is really so, and if it is, can this information help him plan his operations better by forecasting the quantity of his engineering services required by construction firms in each quarter of the year? The following table presents the sales of his services and total amounts of contracts for highway construction over the past eight quarters:
|
QUARTER
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
|
Sales of NCEC Services (in $ thousands)
|
8
|
10
|
15
|
9
|
12
|
13
|
12
|
16
|
|
Contracts Released (in $ thousands)
|
153
|
172
|
197
|
178
|
185
|
199
|
205
|
226
|
a) Using this data, develop a regression equation for predicting the level of demand of NCEC's services.
b) Determine the coefficient of correlation and the standard error of the estimate.