$4.$ If the future value of a one$-$period investment is given by the formula, F $=$ I $+($I $\backslash$times R$),$ what is the formula for the rate of interest, R$?$

R $=$ F $-($I $\backslash$times F$)$

R $=$ I $+($I $\backslash$times F$)$

R $=($F $-$ I$)\backslash$times I

R $=($F $-$ I$)/$I