You have a portfolio of two stocks with the following investment proportions and betas:

Stock $A=30\%$ of the portfolio investment; Beta of stock $A=1\mathrm{.}8$

Stock $B=70\%$ of the portfolio investment; Beta of stock $B=1\mathrm{.}1$

What is the portfolio beta?

$1\mathrm{.}45$

$1\mathrm{.}98$

$1\mathrm{.}31$

$1\mathrm{.}63$