To get $700 after 4years at 3%compounded monthly

3%     x 
100   $700   
                        Cross multiply and divide your only number which is 100.. 3 is your percent so it has to be over 100 and your x is your variable, your unknown number over $700 Set it up like a Fraction ! 3 times 700= 2,100 divide it by 100 which is equaled to 21 So 21 is like your percent !! Hope this helped...