Each of 150 newly manufactured items is examined and the number of scratches per item is...

Each of 150 newly manufactured items is examined and the number of scratches per item is recorded (the items are supposed to be free of scratches), yielding the following data:

Let X = the number of scratches on a randomly chosen item, and assume that X has a Poisson distribution with parameter μ.

a. Find an unbiased estimator of m and compute the estimate for the data. [Hint: E(X) = μ for X Poisson, so ?]

b. What is the standard deviation (standard error) of your estimator? Compute the estimated standard error. [Hint: σ²_xfor X Poisson.]