Given the monthly returns that follow, find the R$2$

Month Portfolio Return $(\%)$ S&P $500$ Return $(\%)$

January $55\mathrm{.}3$

February $-2\mathrm{.}4-3$

March $-1\mathrm{.}7-0\mathrm{.}8$

April $2\mathrm{.}25$

May $0\mathrm{.}70$

June $-0\mathrm{.}9-0\mathrm{.}4$

July $00\mathrm{.}5$

August $1\mathrm{.}72\mathrm{.}2$

September $10\mathrm{.}1$

October $-3\mathrm{.}6-4\mathrm{.}3$

November $42\mathrm{.}3$

December $0\mathrm{.}70\mathrm{.}5$

Answers:

$0\mathrm{.}913$

$0\mathrm{.}814$

$0\mathrm{.}834$

$0\mathrm{.}818$