You've invested all your financial wealth in two exchange$-$traded funds: SPY$,$ that tracks the S&P$500$ Index, and GTIP, that invests exclusively in US governmental bonds.

Suppose that currently the average returns of SPY and GTIP are respectively $12\%$ and $4\%.$

Suppose also that currently you hold $$1\mathrm{.}5$ million in SPY and $$1$ million in GTIP.

Questions:

$($A$)$ What proportion of your portfolio $($weight$)$ are you currently investing in SPY$?$

$($B$)$ What proportion of your portfolio $($weight$)$ are you currently investing in GTIP?

$($C$)$ What is the current average return of your portfolio?

$($D$)$ If you want to rebalance your portfolio to achieve a target average return of $10\%,$ what proportion your portfolio $($weight$)$ should you put in SPY and what proportion should you put in GTIP?