Exam 22: Time Series Analysis

Consider the following to answer the question(s) below: Annual estimates of the population in a certain city from 1999 (t = 1) onward are shown in the time series graph below. -The dominant component in this time series is

Annual estimates of the population in the age group 65+ in a certain city from 1999 (t = 1) onward are used to estimate the following quadratic trend model: Using this model, the estimate for 2008 is

Consider the following to answer the question(s) below: The quarterly sales of all types of bicycles sold at a small sporting goods store in Charlottetown for the 16 quarters from January 2005 to December 2008 are depicted in the time series graph below. -Which of the following statements best describes this data and model?

Consider the following to answer the question(s) below: A company has developed a linear trend model to forecast monthly sales. The following data show the actual sales and the "fitted" sales for months 1-12. -Based on these data, what is the mean absolute deviation (MAD) for the linear trend model?

Assume that the year 2000 is used as the index base period and that sales were $12 million in the year 2000. If sales were $18 million in the year 2006, the simple index number for the year 2006 is

A large automobile parts supplier, keeps track of the demand for a particular part needed by its customers, automobile manufacturers. The time series plot below shows monthly demand for this part (in thousands) for a five year period. a. Identify the dominant time series component (s) in the data. b. Suppose that the single exponential smoothing (SES) model was applied to these data. Below are time series graphs showing SES results using two different smoothing constants (α = 0.2 and α = 0.8). In which application is a larger value of α used? I. ii. c. What forecasting method may be a better choice than SES for these data? Explain.

The following table shows actual sales values and forecasts provided by two different methods. a. Calculate the MAD for each method. b. Calculate the MSE for each method. c. Which method forecasts better?

Consider the following to answer the question(s) below: A company has developed a linear trend model to forecast monthly sales. The following data show the actual sales and the "fitted" sales for months 1-12. -Based on these data, what is the mean absolute percentage error (MAPE) for the linear trend model?