Step 1 :The problem is asking for the probability that exactly 10 cars will arrive at a McDonald's drive-thru between 5:00 PM and 6:00 PM, given that cars arrive at a rate of 20 cars per hour.
Step 2 :We can use the given formula to calculate this probability: \(P(x)=\frac{20^{x} e^{-20}}{x !}\), where \(x !\) is the factorial of \(x\), and \(x\) is the number of cars.
Step 3 :Substitute \(x=10\) into the formula: \(P(10)=\frac{20^{10} e^{-20}}{10 !}\).
Step 4 :Calculate the result, which is approximately 0.005816306518345136.
Step 5 :However, the problem asks for the answer to be rounded to two decimal places. So, we round the result to 0.01.
Step 6 :Final Answer: The probability that exactly 10 cars will arrive between 5:00 PM and 6:00 PM is \(\boxed{0.01}\).