The data in FB represent the number of Facebook users (quarterly, in millions) worldwide between the first quarter of 2009 and the second quarter of 2018.

a. Plot the series of data.

b. Compute a linear trend forecasting equation and plot the results.

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 number of Facebook users worldwide for the third quarter of 2018 and the fourth quarter of 2018 .

g. Based on the most appropriate model, when would the number of Facebook users reach 3 billion?