One way that researchers study the effects of trans fats on people's health is by setting up controlled experiments. for example, in an experimental feeding trial, participants agree to stick to specific diets that the researchers prescribe. in this case, the researchers might vary the proportions of saturated, unsaturated, and trans fats in the diet of each participant. throughout the study, the health status of the participants is monitored closely. suppose that you are a researcher designing an experimental feeding trial. how would you set up your study and what limitations would you face?

Annuity payments are assumed to come at the end of each payment period (termed an ordinary annuity). however, an exception occurs when the annuity payments come at the beginning of each period (termed an annuity due). what is the future value of a 13-year annuity of $2,800 per period where payments come at the beginning of each period? the interest rate is 9 percent. use appendix c for an approximate answer, but calculate your final answer using the formula and financial calculator methods. to find the future value of an annuity due when using the appendix tables, add 1 to n and subtract 1 from the tabular value. for example, to find the future value of a $100 payment at the beginning of each period for five periods at 10 percent, go to appendix c for n = 6 and i = 10 percent. look up the value of 7.716 and subtract 1 from it for an answer of 6.716 or $671.60 ($100 × 6.716)