Revision as of 08:18, 26 May 2023 by Admin (Created page with "Dental claims experience was collected on 6480 policies. There were a total of 9720 claims on these policies. The following table shows the number of dental policies having va...")
May 26'23
Exercise
Dental claims experience was collected on 6480 policies. There were a total of 9720 claims on these policies. The following table shows the number of dental policies having varying numbers of claims.
Number of Claims | Number of Policies |
---|---|
0 | 1282 |
1 | 2218 |
2 | 1856 |
3 | 801 |
4 | 235 |
5 | 81 |
6 or more | 7 |
Total | 6480 |
Calculate the chi-squared statistic to test if a Poisson model with no predictors provides
an adequate fit to the data.
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May 26'23
Key: C
The average number of claims on a policy is 9720/6480 = 1.5. Using this as the parameter of a Poisson distribution yields the following table of actual (given) and expected (calculated) policies with given numbers of claims:
Number of Claims | ActualNumber of Policies | Poisson Probability | ExpectedNumber of Policies | Chi-square |
---|---|---|---|---|
0 | 1282 | 0.2231 | 1445.69 | 18.53 |
1 | 2218 | 0.3347 | 2168.86 | 1.11 |
2 | 1856 | 0.2510 | 1626.48 | 32.39 |
3 | 801 | 0.1255 | 813.24 | 0.18 |
4 | 235 | 0.0471 | 305.21 | 16.15 |
5 | 81 | 0.0141 | 91.37 | 1.18 |
6 or more | 7 | 0.0045 | 29.16 | 16.84 |
Total | 6480 | 1.0000 | 6480.01 | 86.38 |