The following data set, from a study by Lucas (1985)2 , shows the number of accidents occurring per quarter (three months) at a DuPont company facility, over a 10-year period. The data set has been partitioned 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
|
When the data set was presented in Problem 13.22, it was simply stated as a matter of fact that a Poisson pdf was a reasonable model for representing this data.