Quarterly revenue ($ millions) for twitter for the first quarter of 2012 through the first quarter of 2014 are shown below (adexchange.com, April, 2015):
Quarter Revenue ($ millions)
1..................................54
2..................................68
3..................................82
4.................................112
5.................................114
6.................................139
7.................................169
8.................................243
9.................................250
a. Construct a time series plot. What type of pattern exists in the data?
b. Using excel or Minitab, develop a linear trend equation for this time series.
c. Using excel or Minitab, develop a quadratic trend equation for this time series.
d. Compare the MSE for each model. Which model appears better according to MSE?
e. Use the models developed in parts (b) and (c) to forecast revenue for the tenth quarter.
f. Which of the two forecasts in part (e) would you use? explain.