The file Silver contains the following prices in London for an ounce of silver (in US$) on the last day of the year from 1999 to 2011:

a. Plot the data.
b. Compute a linear trend forecasting equation and plot the trend line.
c. Compute a quadratic trend forecasting equation and plot the results.
d. Compute an exponential trend forecasting equation and plot the results.
e. Which model is the most appropriate?
f. Using the most appropriate model, forecast the price of silver at the end of 2012.