Experience the Tour de France $($ETF$)$ is a specialty travel agent. It arranges vacations for amateur cyclists who want to experience the Tour de France by riding through one or more stages in the race. It has six people who take calls from clients. Each call lasts on average $25$ minutes, with a standard deviation of $50$ minutes. A call arrives on average every $20$ minutes with a standard deviation of $20$ minutes.

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

On average, how many minutes does a caller wait before talking to an agent? minutes