Question: Records pertaining to the monthly number of job-related injuries at an underground coalrnine were being studied by a federal agency. The values for the past 100 months were as follows:
Injuries per month Frequency of occurence
0 35
1 40
2 13
3 6
4 4
5 1
6 1
(a) Apply the chi-square test to these data to test the hypothesis that the underlying distribution is Poisson. Use the level of significance a= 0.05.
(b) Apply the chi-square test to these data to test the hypothesis that the distribution is Poisson with mean 1.0. Again let α = 0.05.
(c) What are the differences between parts (a) and (b), and when might each case arise?