Answer: P(3) = 0.20
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Step-by-step explanation:
The Poisson PDF value is given by the function
P(x) = ( e^(-mu)*mu^x )/(x!)
where the exclamation mark indicates a factorial
In this case, mu = 4, so we can update the equation into
P(x) = ( e^(-4)*4^x )/(x!)
Now plug in x = 3 to finish off the problem
P(x) = ( e^(-4)*4^x )/(x!)
P(3) = ( e^(-4)*4^3 )/(3!)
P(3) = 0.1953668148129
P(3) = 0.20
Note: The 'e' is a special constant which is approximately e = 2.718, similar to how pi = 3.14 is a constant used often.