The following data set, from the same study by Lucas (1985) referenced in Exercise 12.3, shows the actual number of accidents occurring per quarter (three months) separated into two periods: Period I is the ?rst ?ve-year period of the study; Period II, the second ?ve-year period.
|
5
|
5
|
10
|
8
|
3
|
4
|
2
|
0
|
|
4
|
5
|
7
|
3
|
1
|
3
|
2
|
2
|
|
2
|
8
|
6
|
9
|
7
|
7
|
1
|
4
|
|
5
|
6
|
5
|
10
|
1
|
2
|
2
|
1
|
|
6
|
3
|
3
|
10
|
4
|
4
|
4
|
4
|
Provide an appropriate statistical description and summary of this data set; comment on any distinctive characteristics and postulate potential explanations for your observation.