Probability DRV

Question

In a standard army corps, there is an average of 0.61 deaths by horse kick per year. Let X = the number of deaths by horse kicks for corps A in the next years. What distribution does X follow with what parameter(s)?

Answer 1

Hi Chad,

This is a Poisson distribution. Typically:

P(X=k) = Lambda^k*e^-Lambda/k!

X=k= Number of horse kick deaths for group A

Lambda= Expected Value of horse kick deaths per year

e=Euler's Constant, approximately 2.718

BUT....

You were given a rate statistic, not a count, which means we have to convert Lambda:

Lambda = rt;

X=k= Number of horse kick deaths for group A

r= rate of kick deaths per year = 0.61

t= time = 1 year

So new equation is:

P(X=k) = (0.61)^k*e^-0.61/k!

Distribution is Poisson; parameter is rt= 0.61 deaths per year.