University of Florida football programs are printed $1$ week prior to each home game. Attendance averages $90,000$ screaming and loyal Gators fans, of whom two$-$thirds usually buy the program, following a normal distribution, for $$5$ each. Unsold programs are sent to a recycling center that pays only $10$ cents per program. The standard deviation is $5,000$ programs, and the cost to print each program is $$2.$ Refer to the standard normal table for $z-$values.

a$)$ What is the cost of underestimating demand for each program?

$C_s=$$ $($round your response to two decimal places$).$