1) The sales of the air conditioners in the past three years are given here.
a. Plot the time series data. Is any pattern present?
b. Recommend a causal model that can take seasonality into consideration.
c. Fit your proposed model to the data and obtain the summary output.
d. Compute the quarterly forecast for 2012.
2) For the following Time Series data, answer the following questions.
Week | 1 2 3 4 5 6
Value | 219 213 216 211 217 214
Note: Use Excel to answer the questions, whenever possible.
a) Construct a time series plot. Does the series show trend or seasonality?
b) Develop a three-period moving average for this time series.
c) Develop the three-period moving average forecasts for periods 4, 5, 6, and 7.
d) Using exponential smoothing with Ģ = 0.1, forecast the value of time series for period 7.
e) Find the MAE, MSE, and MAPE for both models. Which model is preferred? Why?
3) Using the following yearly data, answer the following questions.
a. Construct a time series plot.
b. Fit a linear trend line to the data.
c. Find the MSE of the linear model.
d. Fit a quadratic trend equation to the data.