Elementary Statistics (12th Edition)

a)mean=$\frac{535}{576}=0.929$. Hence, $P(X=2)=\frac{0.929^2\cdot e^{-0.929}}{2!}=0.17.$ b)The expected number is:$576\cdot 0.17=97.92.$ c) The expected number is really close to the actual result.