Question 17466
First, divide both sides by 1000
{{{1400/1000}}} = {{{(1000(1+(r/360))^720)}}}
1.4 = {{{(1+(r/360))^720}}}
Now take log of both sides
log 1.4 = log {{{(1+(r/360))^720}}}
from the properties of logarithms we know:
log {{{x^n}}} = n log x
so,
log 1.4 = 720 log {{{1+(r/360)}}}
Divide both sides by 720
{{{(log 1.4)/720}}} = {{{1 + (r/360)}}}
{{{(log 1.4)/720}}} - 1 = {{{r/360}}}
{{{((log 1.4)/720 -1) * 360}}} = r
now just use the calculator
hope this helps