a new augmented reality entertainment center opened up at l.a. live, the entertainment complex in downtown los angeles. it costs $10 to gain general admission. once a customer enters, he/she can play unlimited games at $6 per hour. the center knows that the time a customer spends at the center is a random variable with a mean of 2 hours and a standard deviation of 1 hour 12 minutes. how much on average a customer spends per visit to the center? how much is the variability in the typical customer payment per visit?