Question

How long will it take for $2100 to grow to $47200 at an interest rate of 4.5% if the interest is compounded continuously? Round the number of years to the nearest
hundredth

Answer 1

hi,  

you have  then :   2100 * 1.045 ^n  = 47 200

                                         1.045^n = 47200 /2100

                                          1.045^n = 472/21

                                                    n =  ln ( 472/21 )  / ln ( 1.045)

                                                    n ≈71 years

let's check :   2100 *1.045^70 = 45746,68   and  2100 *1.045^71 = 47805.28