Question 128716
The formula for compound interest is:
{{{A = P(1+i)^n}}} where A = present amount, P = the principal invested, i = the interest rate (expressed as a decimal), and n = the number of years.
You may also see this written:
{{{A = P(1+r)^t}}}
In your problem, you will substitute A = $1,440.00, P = $1,000.00, and n = 2 years.  So make the appropriate substitiutions and solve  for r.
{{{1440 = 1000(1+r)^2}}} Divide both sides by 1000
{{{1.44 = (1+r)^2}}} Take the square root of both sides.
{{{1.2 = 1+r}}} Subtract 1 from both sides.
{{{0.2 = r}}} Multiply by 100 to convert to percent.
r = 20%