Answer
$P(7)=\frac{(3.4\times3)^7}{7!}e^{-3.4\times3}=\frac{(10.2)^7}{5040}e^{-10.2}=0.0847$
On about 847 of every 10,000 3 miles of randomly selected highway, there will be exactly 7 potholes.
Work Step by Step
$P(x)=\frac{(λt)^x}{x!}e^{-λt}$
λ = 3.4 -> (3.4 potholes per mile)
t = 3 -> (3 miles)
$P(7)=\frac{(3.4\times3)^7}{7!}e^{-3.4\times3}=\frac{(10.2)^7}{5040}e^{-10.2}=0.0847$
