
investment returns



	return = final value / initial value - 1


	e.g.  109 / 100 - 1

		= 0.09

		= 9%		




over several time periods


	a x b x c



	1.08 x 1.05 x 1.06


	= 1.20204


	= 20.2 %




converted to an annual rate

	
	a ^ (1 / number_of_years)




	return over 3 years = 25%

	1.25 ^ (1/3)

	1.077217


	= 7.7% p.a.	(per annum, equivalent rate over 1 year)



