```
cipoisson(4) # 95\% confidence limit
# lower upper
# 1.089865 10.24153
ppois(4, 10.24153) #chance of seeing 4 or fewer events with large rate
# [1] 0.02500096
1-ppois(3, 1.08986) #chance of seeing 4 or more, with a small rate
# [1] 0.02499961
```

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