Below is the question that I am having difficulty with.

Below is the question that I am having difficulty with. I used a similar questions mathematics to try and solve it myself but I keep getting the wrong answer and I keep getting different answers as well. I fear that I am doing the formula incorrectly. Can anyone please provide guidance?

During the morning hours at a catalog sales department, telephone calls come in at the rate (Poisson) of 36 per hour. Calls that cannot be answered immediately are put on hold. The system can handle 8 callers on hold. If additional calls come in, they receive a busy signal. The 3 customer service representatives who answer the calls spend an average of 3 minutes with a customer. Use Table 1 and Table 2.

What is the probability that a caller will get a busy signal? (Hint: Solve for log K or ln K using trial and error.) (Do not round intermediate calculations. Round your answer to 5 decimal places.)

(Do not round intermediate calculations. Round your answer to 3 decimal places.)