Problem $10-22($Algo$)$

You are planning employees for a bank. You plan for $7$ tellers. Tellers take $10$ minutes per customer, with a standard deviation of $5$ minutes. Customers will arrive one every $2$ minutes according to an exponential distribution $($recall that the standard deviation is equal to the mean$).$ Every customer who arrives eventually gets serviced. Use waiting line approximation to answer the following questions.

a$.$ On average, how many customers would be waiting in line? Note: Round your intermediate calculations to $4$ decimal places and final answer to $3$ decimal places.

Number of customers

b$.$ On average, how long would a customer spend in the bank? Note: Round your intermediate calculations to $4$ decimal places and final answer to $3$ decimal places.

Time spent by a customer

$10\mathrm{.}298$ minutes