Answer
The native American population of Washington state is 103 thousand.
The native American population of California is 309 thousand.
Work Step by Step
Let $w$ be the native American population of Washington state.
The native American population of California is $3w$.
$w+3w=412$ $\longrightarrow$combine like terms
$4w=412$ $\longrightarrow$multiplication property
$4w\div4=412\div4$ $\longrightarrow$simplify
$w=103$
$3w=3\times103=309$
