The ATM at a local convenience store allows customers to make withdrawals of $10, $20, $50, or $100. Let  denote a random variable that indicates the amount withdrawn by a customer. The probability...

The ATM at a local convenience store allows customers to make withdrawals of $10, $20, $50, or $100. Let
 denote a random variable that indicates the amount withdrawn by a customer. The probability distribution of
 is

(a) Draw the probability distribution of
.

(b) What is the probability that a customer withdraws more than $20?

(c) What is the expected amount of money withdrawn by a customer?

(d) The expected value is not a possible value of the amount withdrawn. Interpret the expected value for a manager.

(e) Find the variance and standard deviation of
.