An individual has $$30,000$ invested in a stock with a beta of $0\mathrm{.}9$ and another $$15,000$ invested in a stock with a beta of $1\mathrm{.}3.$ If these are the only two investments in her portfolio, what is her portfolio beta?

Group of answer choices

$1\mathrm{.}03$

$1\mathrm{.}17$

$5\mathrm{.}25$

$1\mathrm{.}31$

$1\mathrm{.}10$