Exam 16: Analyzing and Forecasting Time-Series Data

Suppose an economist has developed a model for forecasting annual consumption,y_t,as function of total labor income,x₁_t ,and total property income,x₂_t based on 20 years on annual data.The following regression model has been developed: = 7.81 + 0.91x₁_t+ 0.57x₂_t with the standard error = 1.29 and the Durbin-Watson d statistic = 2.09.Using an alpha = .05,which of the following conclusions should be reached?

(Multiple Choice)

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Question 101

Forecast bias measures the average amount of error per forecast,so a positive value means that forecasts tended to be too low.

(True/False)

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Question 102

Which of the following is true about index numbers? Index numbers are:

(Multiple Choice)

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Question 103

A company's annual sales are shown below in thousands of dollars for a period of 10 years. Plot the time series; find the linear regression model,and also the forecast value and error for each of the years.Also discuss whether you think a linear model appears to be appropriate.

(Essay)

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Question 104

If the historical data on which the model is being built consist of weekly data,the forecasting period would also be weekly.

(True/False)

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Question 105

Because simple exponential smoothing models require a starting point for the first period forecast that will be arbitrary,it is important to have as much data as possible to dampen out the effect of the starting point.

(True/False)

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Question 106

It is possible to conduct a statistical test for autocorrelation using the Durbin-Watson test and not be able to make a definitive conclusion about whether there is autocorrelation or not based on the data.

(True/False)

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Question 107

From an annual time series of a company's sales the linear trend model F_t = 127 + 54(t)has been developed.This means that on average sales have been increasing by 127 per year.

(True/False)

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Question 108

In a single exponential smoothing model,a large value for the smoothing constant will result in greater smoothing of the data than will a smoothing constant close to zero.

(True/False)

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Question 109

A time-series graph shows that annual sales data have grown gradually over the past 10 years.Given this,if a linear trend model is used to forecast future years' sales,the sign on the regression slope coefficient will be positive.

(True/False)

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Question 110

After a linear forecasting model is found for a time series,if the Durbin-Watson statistic is less than d_L this means that:

(Multiple Choice)

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Question 111

Stock analysts have recently stated in a meeting on Wall Street that over the past 50 years there have been periods of high market prices followed by periods of lower prices but over time prices have moved upwards.Given their statement,stock prices most likely exhibit only trend and cyclical components.

(True/False)

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Question 112

The All American Toy Company has a very seasonal sales pattern.Sales are high during the fall quarter,drop off substantially in the winter quarter and are more typical during spring and summer quarters.The following historical data exist for the past 16 quarters. Based on these data,develop a seasonally adjusted forecast for the four quarters of 2002 using a linear trend regression model.

(Essay)

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Question 113

Gibson,Inc.is a holding company that owns several businesses.One such business is a truck sales company.To help in managing this operation,managers at Gibson have collected sales data for the past 20 years showing the number of trucks sold each year.They have then developed the linear trend forecasting model shown as ollows: Based on this information,the fitted value for year 1 is about 99.

(True/False)

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Question 114

If a time-series plot indicates that the data do not appear to exhibit a trend,then a double exponential smoothing model would likely be the most appropriate to use rather than simple exponential smoothing model.

(True/False)

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Question 115

In a recent meeting,a manager indicated that sales tend to be higher during October,November,and December and lower in the spring.In making this statement,she is indicating that sales for the company are cyclical.

(True/False)

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Question 116

In comparing two or more forecasting models,the MAD value is useful in determining how successful the models were in fitting historical data.

(True/False)

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Question 117

The owners of Hal's Cookie Company have collected sales data for the past 8 months.These data are shown as follows: Using a smoothing constant of 0.4,the forecast value for period 3 is 112.

(True/False)

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Question 118

A stockbroker at a large brokerage firm recently analyzed the combined annual profits for all firms in the airline industry.One time-series component that may have been present in these annual data was a seasonal component.

(True/False)

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Question 119

If a smoothing model is applied with a smoothing constant exceeding 0.50,the forecasting bias will tend to be positive in most cases.

(True/False)

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Question 120

Showing 101 - 120 of 133

Forecast bias measures the average amount of error per forecast,so a positive value means that forecasts tended to be too low.

Which of the following is true about index numbers? Index numbers are:

A company's annual sales are shown below in thousands of dollars for a period of 10 years. Plot the time series; find the linear regression model,and also the forecast value and error for each of the years.Also discuss whether you think a linear model appears to be appropriate.

If the historical data on which the model is being built consist of weekly data,the forecasting period would also be weekly.

Because simple exponential smoothing models require a starting point for the first period forecast that will be arbitrary,it is important to have as much data as possible to dampen out the effect of the starting point.

It is possible to conduct a statistical test for autocorrelation using the Durbin-Watson test and not be able to make a definitive conclusion about whether there is autocorrelation or not based on the data.

From an annual time series of a company's sales the linear trend model F_t = 127 + 54(t)has been developed.This means that on average sales have been increasing by 127 per year.

In a single exponential smoothing model,a large value for the smoothing constant will result in greater smoothing of the data than will a smoothing constant close to zero.

A time-series graph shows that annual sales data have grown gradually over the past 10 years.Given this,if a linear trend model is used to forecast future years' sales,the sign on the regression slope coefficient will be positive.

After a linear forecasting model is found for a time series,if the Durbin-Watson statistic is less than d_L this means that:

If a time-series plot indicates that the data do not appear to exhibit a trend,then a double exponential smoothing model would likely be the most appropriate to use rather than simple exponential smoothing model.

In a recent meeting,a manager indicated that sales tend to be higher during October,November,and December and lower in the spring.In making this statement,she is indicating that sales for the company are cyclical.

In comparing two or more forecasting models,the MAD value is useful in determining how successful the models were in fitting historical data.

The owners of Hal's Cookie Company have collected sales data for the past 8 months.These data are shown as follows: Using a smoothing constant of 0.4,the forecast value for period 3 is 112.

A stockbroker at a large brokerage firm recently analyzed the combined annual profits for all firms in the airline industry.One time-series component that may have been present in these annual data was a seasonal component.

If a smoothing model is applied with a smoothing constant exceeding 0.50,the forecasting bias will tend to be positive in most cases.

The Where, why, and How of Data Collection

Graphs,charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Using Probability and Probability Distributions

Discrete Probability Distributions

Introduction to Continuous Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Introduction to Nonparametric Statistics

Introduction to Quality and Statistical Process Control

Introduction to Decision Analysis

Filters

Exam 16: Analyzing and Forecasting Time-Series Data

Forecast bias measures the average amount of error per forecast,so a positive value means that forecasts tended to be too low.

Which of the following is true about index numbers? Index numbers are:

A company's annual sales are shown below in thousands of dollars for a period of 10 years. Plot the time series; find the linear regression model,and also the forecast value and error for each of the years.Also discuss whether you think a linear model appears to be appropriate.

If the historical data on which the model is being built consist of weekly data,the forecasting period would also be weekly.

Because simple exponential smoothing models require a starting point for the first period forecast that will be arbitrary,it is important to have as much data as possible to dampen out the effect of the starting point.

It is possible to conduct a statistical test for autocorrelation using the Durbin-Watson test and not be able to make a definitive conclusion about whether there is autocorrelation or not based on the data.

From an annual time series of a company's sales the linear trend model Ft = 127 + 54(t)has been developed.This means that on average sales have been increasing by 127 per year.

In a single exponential smoothing model,a large value for the smoothing constant will result in greater smoothing of the data than will a smoothing constant close to zero.

A time-series graph shows that annual sales data have grown gradually over the past 10 years.Given this,if a linear trend model is used to forecast future years' sales,the sign on the regression slope coefficient will be positive.

After a linear forecasting model is found for a time series,if the Durbin-Watson statistic is less than dL this means that:

If a time-series plot indicates that the data do not appear to exhibit a trend,then a double exponential smoothing model would likely be the most appropriate to use rather than simple exponential smoothing model.

In a recent meeting,a manager indicated that sales tend to be higher during October,November,and December and lower in the spring.In making this statement,she is indicating that sales for the company are cyclical.

In comparing two or more forecasting models,the MAD value is useful in determining how successful the models were in fitting historical data.

The owners of Hal's Cookie Company have collected sales data for the past 8 months.These data are shown as follows: Using a smoothing constant of 0.4,the forecast value for period 3 is 112.

A stockbroker at a large brokerage firm recently analyzed the combined annual profits for all firms in the airline industry.One time-series component that may have been present in these annual data was a seasonal component.

If a smoothing model is applied with a smoothing constant exceeding 0.50,the forecasting bias will tend to be positive in most cases.

The Where, why, and How of Data Collection

Graphs,charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Using Probability and Probability Distributions

Discrete Probability Distributions

Introduction to Continuous Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Introduction to Nonparametric Statistics

Introduction to Quality and Statistical Process Control

Introduction to Decision Analysis

Filters

From an annual time series of a company's sales the linear trend model F_t = 127 + 54(t)has been developed.This means that on average sales have been increasing by 127 per year.

After a linear forecasting model is found for a time series,if the Durbin-Watson statistic is less than d_L this means that: