Exam 16: Time Series Forecasting and Index Numbers

Box-Jenkins methodology transforms nonstationary time series values into stationary time series values.

A ____________ index is a weighted aggregate price index.It is accurate in its calculation of periodic prices.However,when using this index,it is difficult to compare the prices in different time periods.

The demand for a product for the last six years has been 15,15,17,18,20,and 19.The manager wants to predict the demand for this time series using the following simple linear trend equation: tr_t = 12 + 2t.Use this equation to forecast the demand for this product,and then calculate the MSD.

Consider a time series with 15 quarterly sales observations.Using the quadratic trend model,the following partial computer output was obtained.

Given the following data,compute the total error (sum of the error terms).

Two forecasting models were used to predict the future values of a time series.The forecasts are shown below with the actual values:

The smoothing constant is a number that determines how much weight is attached to each observation.

When using simple exponential smoothing,the value of the smoothing constant α cannot be:

Removing the seasonal effect by dividing the actual time series observation by the estimated seasonal factor associated with the time series observation is called deseasonalization.

The basic difference between MAD and MSE is that MSE,unlike MAD,penalizes a forecasting technique much more for _________ errors than for _________ errors.

A major drawback of the aggregate price index is that:

In general,the number of dummy variables used to model constant seasonal variation is equal to the number of:

Consider the quarterly production data (in thousands of units)for the XYZ manufacturing company below.The normalized (adjusted)seasonal factors are winter = .9982,spring = .9263,summer = 1.139,and fall = .9365.

Use the following price information for three grains.

In the multiplicative decomposition method,the centered moving averages provide an estimate of a trend's ____________.

The purpose behind moving averages and centered moving averages is to eliminate __________________.

Two forecasting models were used to predict the future values of a time series.The forecasts are shown below with the actual values:

Weighting in exponential smoothing is accomplished by using _____________.

The following data on prices and quantities for the years 1995 and 2000 are given for three products.

Given the following data,compute the mean squared deviation (error).