User Tools


Differences

This shows you the differences between two versions of the page.

Link to this comparison view

math-340:m340-f15-hw:hw-9 [2015/09/15 06:33] – created dcsmath-340:m340-f15-hw:hw-9 [2015/09/20 09:34] (current) dcs
Line 12: Line 12:
   - $X$ is the number of heads in four tosses of a fair coin.   - $X$ is the number of heads in four tosses of a fair coin.
   - $Y$ is number of aces when two cards are drawn a random from a standard deck of 52 cards.   - $Y$ is number of aces when two cards are drawn a random from a standard deck of 52 cards.
 +
 +Answers:
 +
 +  - $p_X(x) = \begin{cases}\frac{3}{5},& \text{if } x = 2, \\ \frac{2}{5},& \text{if } x = 3, \\ 0,& \text{otherwise}.\end{cases}$
 +  - $p_X(x) = \begin{cases}\frac{1}{16},& \text{if } x = 0, \\ \frac{1}{4},& \text{if } x = 1, \\ \frac{3}{8},& \text{if } x = 2, \\ \frac{1}{4},& \text{if } x = 3, \\ \frac{1}{16},& \text{if } x = 4, \\ 0,& \text{otherwise}. \end{cases}$
 +  - $p_Y(y) = \begin{cases}\frac{188}{221},& \text{if } y = 0, \\ \frac{32}{221},& \text{if } y = 1, \\ \frac{1}{221},& \text{if } y = 2, \\ 0,& \text{otherwise}.\end{cases}$
 +