Data on the number of occurrences per time period and observed frequencies follow. Use = .05

Question:

Data on the number of occurrences per time period and observed frequencies follow. Use α = .05 and the goodness of fit test to see whether the data fit a Poisson distribution.
Number of Occurrences Observed Frequency
0 ...............39
1 ...............30
2 ...............30
3 ...............18
4 ............... 3