abled: Ch$2$ Test $2$

i

Required information

A computer sends a packet of information along a channel and waits for a return signal acknowledging that the packet has been received. If no acknowledgment is received within a certain time, the packet is re$-$sent. Let $x$ represent the number of times the packet is sent. Assume that the probability mass function of $x$ is given by

$p(x)=\{\begin{array}{ccc}cx& \text{f}\text{o}\text{r}x=1,2\text{d}\text{o}\text{t}\text{s}\text{,}& 7\\ 0& \text{o}\text{t}\text{h}\text{e}\text{r}\text{w}\text{i}\text{s}\text{e}& \end{array}$

where $c$ is a constant. Express the answers in decimals.

$P(x=2)$