In: Statistics and Probability
In a game of cards you win $1 if you draw an even number, $2 if you draw diamonds, $5 if you draw a king and $10 if you draw the queen of diamonds. You get nothing for any other card that you draw.
Suppose, random variable X denotes amount of money (in dollars) gained.
It is given that $10 is won in case of queen of diamonds.
It is given that $5 is won in case of any of four kings.
It is given that $2 is won in case of any of 13 diamonds. However, for queen of diamonds another higher amount prize is there.
It is given that $1 is won in case of any of 5*4 = 20 even number cards. However, for 5 even number cards (2 , 4, 6, 8 and 10) of diamonds another higher amount prize is there.
For remaining of the cards, there is no prize money.
(a)
Expected win is given by
(b)
Variance is given by
So, standard deviation is given by