testing - two sample discrete poisson

This may be a simple problem but my answer is not matching with the given answer. Can anyone help me to find just lambda1 & lambda2? Rest I will do. Given answer is (-13.162, 37.162)

 

Lambda 1 and 2 will be the values given for robberies. (123,111)

This is because the parameter of Poisson distribution refers to the rate at which an event takes place.
Here, the robberies are taking place at this rate

 

Thank you. And n1=n2=1 ?

 

No that will also be the number of robberies given.