Exam 16: Time Series and Forecasting

A plastics manufacturer performed a quarterly time series analysis for demands over the last five years (periods 1 through 20). The analysis resulted in the following trend equation and seasonal indexes: Ŷ = 920.0 + 22.6t Ŷ Based on the seasonal indexes, which quarter is expect to have 25% less demand than predicted by the trend line?

Product sales since 1999 are: The least squares trend equation is given as Ŷ = 265.12 - 21.18t, where t is set equal to one for 1999. What were the predicted sales in 2006?

What is removed from a time series when the data is divided by the seasonal indexes? __

How can you describe the moving average method?

When estimating the specific seasonals for a monthly time series, the sum of the 12 modified means should theoretically be equal to 1,200 because the average of the 12 specific seasonals is designated as 100.

Using the following time series data, The quarterly indexes for the year 2010 will total approximately _______.

If the trend equation is Ŷ = 10 + 100t, the forecasted value increases 100 units for the next time period, t.

For the third quarter, the sales are 2,000 units; the seasonal index for the quarter is 0.80. What are the deseasonalized sales for the quarter?

What time series component was exemplified during the 1980's when the American economy enjoyed a period of prosperity?

Autocorrelation in a time series can be tested using ____.

In a time series, high sales in the summer and low sales in the winter is called?

The table below shows the sales for a resort hotel recorded over the past year. The seasonal indexes for each quarter are also provided. To track the trend for these four quarters, use the indexes to deseasonalize the sales data Overall, sales are:

Autocorrelation is measured by the trend component of a time series.

The forecast for the third quarter is 3,000 units; the seasonal index for the quarter is 1.05. What are the seasonally adjusted sales for the quarter?

A typical seasonal index of 103.7 for January indicates that sales for January are below the annual average.

The forecast for the third quarter is 3,000 units; the seasonal index for the quarter is 0.75. What are the seasonally adjusted sales for the quarter?

In the linear trend equation, the letter "b" is the average change in Ŷ for each change of one unit (either increase or decrease) in t.

The trend forecast equation is Ŷ = 120+ 100t. The next forecast is for period 11. The typical seasonal index for period 11 is 0.82. What are the forecast sales for period 11?

The table below shows the sales for a plastics manufacturer recorded over the past year. The seasonal indexes for each quarter are also provided. To track the trend for these four quarters, use the indexes to deseasonalize the sales data Overall, sales are:

Autocorrelation occurs when successive residuals are ____.