Let X denote the number of alpha particles emitted by a sample of Barium-133 in one tenth of a second. The following 50 observations of X were taken with a Geiger counter in a fixed position: 7 4 3 6 4 4 5 3 5 3
5 5 3 2 5 4 3 3 7 6
6 4 3 11 9 6 7 4 5 4
7 3 2 8 6 7 4 1 9 8
4 8 9 3 9 7 7 9 3 10

The experimenter is interested in determining whether X has a Poisson distribution.

a. What is λMLE for the parameter λ of a Poisson distribution? Compute λMLE for the above data.
b. Partition the set of outcomes for this experiment into the sets A1 = {0, 1, 2, 3}, A2 = {4}, A3 = {5}, A4 = {6}, A5 = {7}, and A6 = {8,9,10,...}. Assuming X ∼ Poisson(λMLE), compute P(X ∈ Ai) for i = 1,...,6.
c. Use a Chi-square test with the above partition to test:

H0 : X ∼ Poisson(λMLE),
H1 : X ∼/ Poisson(λMLE).