The number of cars passing over a certain bridge between 11pm and midnight has a Poisson density with lambda = 4.
In what proportion of nights would you expect more than one car to pass over the bridge during this time?
I've already worked out, reading off values from the poisson table http://mat.iitm.ac.in/home/vetri/public_html/statistics/poisson.pdf
1 car would be 0.0916
2 car would be 0.2381
3 car would be 0.4335
4 car would be 0.6288
How would you work out the value for "at least 1"? I thought that it might just be the sum of all these values but then I realised all these values are cumulative, so would it be:
The value for 4 - The value for 1?
0.6288 - 0.0916?