An "Instant Lottery" Is Played by Buying a Ticket and Scratching

Short Answer

An "instant lottery" is played by buying a ticket and scratching off a coating to reveal whether or not you have won a prize, and if so, how much. Suppose an instant lottery pays $5 with probability 0.05 and $100 with probability 0.006. Otherwise it pays nothing. Define
X = amount won for a single ticket. (You can ignore the cost of the ticket.)
-Calculate the standard deviation of X.
$________