Solution
= Solution
The possible values are $y\in\{1,4,7\}$. Each occurs for four of the twelve equally weighted values of $x$, so
$$
\boxed{\mathbb P(y=1)=\mathbb P(y=4)=\mathbb P(y=7)=\frac13.}
$$
= Solution
The possible values are $y\in\{1,4,7\}$. Each occurs for four of the twelve equally weighted values of $x$, so
$$
\boxed{\mathbb P(y=1)=\mathbb P(y=4)=\mathbb P(y=7)=\frac13.}
$$