Question 1

An annual time series cannot exhibit a seasonal component.

Accepted Answer

A) True 
 B)False

Question 2

The Boxer Company has been in business since 1998.The following sales data are recorded by quarter for the years 1999-2001.   The managers at the company wish to determine the seasonal indexes for each quarter during the year.The first step in the process is to remove the seasonal and random components.To do this,they will begin by computing a four period moving average.What is the four-period moving average based on Winter 99 - Fall 99?

Accepted Answer

A) 280 
B) 70 
C) 60 
D) 55 
A) 280 
B) 70 
C) 60 
D) 55

Question 3

Model specification is the process of determining how well a forecasting model fits the past data.

Accepted Answer

A) True 
 B)False

Question 4

A plot of the time series with time on the horizontal axis is an effective means of assessing whether the series is linear or nonlinear.

Accepted Answer

A) True 
 B)False

Question 5

A time series is shown below.Perform single exponential smoothing for this data set using α = 0.2.   What is the value of the forecast for period 6?

Accepted Answer

A) 40 
B) 36 
C) 31.5 
D) 33.2 
A) 40 
B) 36 
C) 31.5 
D) 33.2

Question 6

Which of the following time-series components can be identified when a company has 12 weeks of data beginning January and extending through March?

Accepted Answer

A) Seasonal component 
B) Random component 
C) Trend component 
D) Both B and C 
A) Seasonal component 
B) Random component 
C) Trend component 
D) Both B and C

Question 7

In a double smoothing model,large values for the two smoothing constants will result in greater smoothing of the time series.

Accepted Answer

A) True 
 B)False

Question 8

The Zocor Company is interested in forecasting period 13 sales for a product.It has 12 months of historical data.The following shows the data and the forecasted values for periods 1-12 using a single exponential smoothing model with a smoothing constant value equal to 0.20.   Which of the following would be the forecast for period 13?

Accepted Answer

A) 40.3 
B) 39.2 
C) 34.7 
D) 36.5 
A) 40.3 
B) 39.2 
C) 34.7 
D) 36.5

Question 9

One of the disadvantages of a regression-based linear trend forecasting model is that the forecast errors are computed for time periods that were used in developing the forecasting model and thus do not truly measure the forecasting ability of the model.

Accepted Answer

A) True 
 B)False

Question 10

If the forecast errors are autocorrelated,this is a good indication that the model has been specified correctly.

Accepted Answer

A) True 
 B)False

Question 11

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 value for the mean absolute deviation for months 1-12?

Accepted Answer

A) Approximately 975 
B) About 81 
C) Nearly 150 
D) None of the above. 
A) Approximately 975 
B) About 81 
C) Nearly 150 
D) None of the above.

Question 12

Which of the following is true about deseasonalizing data?

Accepted Answer

A) The sum of the seasonal indexes should be 1.0. 
B) The time series is deseasonalized by multiplying each value by its seasonal index. 
C) Deseasonalizing a time series reduces autocorrelation. 
D) Deseasonalizing a time series can make it easier to see a trend. 
A) The sum of the seasonal indexes should be 1.0. 
B) The time series is deseasonalized by multiplying each value by its seasonal index. 
C) Deseasonalizing a time series reduces autocorrelation. 
D) Deseasonalizing a time series can make it easier to see a trend.

Question 13

If the Durbin-Watson d statistic has a value close to 2,there is reason to believe that there is no autocorrelation between the forecast errors.

Accepted Answer

A) True 
 B)False

Question 14

In a simple exponential smoothing model,which of the following statements is true?

Accepted Answer

A) The forecast values are determined by computing a moving average of the previous 4 data periods if we are working with quarterly data. 
B) The larger the smoothing constant,the more smoothing that takes place in the model. 
C) If the data contain a lot of random or irregular ups and downs,then a larger smoothing constant should be used in an attempt to model these fluctuations. 
D) More smoothing of the data will take place if a smoothing constant value close to zero is used. 
A) The forecast values are determined by computing a moving average of the previous 4 data periods if we are working with quarterly data. 
B) The larger the smoothing constant,the more smoothing that takes place in the model. 
C) If the data contain a lot of random or irregular ups and downs,then a larger smoothing constant should be used in an attempt to model these fluctuations. 
D) More smoothing of the data will take place if a smoothing constant value close to zero is used.

Question 15

The Wilson Company is interested in forecasting demand for its XG-667 product for quarter 13 based on 12 quarters of data.The following shows the data and the double exponential smoothing model results for periods 1-12 using alpha = 0.20 and beta = 0.40.   Based on this information,which of the following statements is true?

Accepted Answer

A) If beta is changed to 0.20 and alpha remains at 0.20,the MAD for periods 2-12 is reduced. 
B) If beta is changed to 0.20 and alpha remains at 0.20,the forecast for period 13 is slightly reduced. 
C) The forecast bias for periods 2-12 is approximately 6.18. 
D) All of the above are true. 
A) If beta is changed to 0.20 and alpha remains at 0.20,the MAD for periods 2-12 is reduced. 
B) If beta is changed to 0.20 and alpha remains at 0.20,the forecast for period 13 is slightly reduced. 
C) The forecast bias for periods 2-12 is approximately 6.18. 
D) All of the above are true.

Question 16

The most useful tool to identify the trend component of a time series is

Accepted Answer

A) moving averages. 
B) exponential smoothing. 
C) regression analysis. 
D) the MAD approach. 
A) moving averages. 
B) exponential smoothing. 
C) regression analysis. 
D) the MAD approach.

Question 17

Which of the following time-series components is almost always present in sales data for electronics companies?

Accepted Answer

A) Random 
B) Trend 
C) Seasonal 
D) All of the above. 
A) Random 
B) Trend 
C) Seasonal 
D) All of the above.

Question 18

A time-series plot that exhibits a general increase in value from the early periods to the latest time periods:

Accepted Answer

A) most likely is exhibiting a cyclical component. 
B) has a trend component present in the data. 
C) will probably start to decline in a few periods. 
D) has a seasonal component present in the data 
A) most likely is exhibiting a cyclical component. 
B) has a trend component present in the data. 
C) will probably start to decline in a few periods. 
D) has a seasonal component present in the data

Question 19

Renton Industries makes replacement parts for the automobile industry.As part of the company's capacity planning,it needs a long-range total demand forecast.The following information was generated based on 10 years of historical data on total number of parts sold each year.   Based on this information,the percent of variation in the number of parts sold that is explained by the linear trend model is approximately 90.9.

Accepted Answer

A) True 
 B)False

Question 20

The Boxer Company has been in business since 1998.The following sales data are recorded by quarter for the years 1999-2001.   Which of the following time-series components are present in these data?

Accepted Answer

A) Trend component 
B) Seasonal component 
C) Random component 
D) All of the above. 
A) Trend component 
B) Seasonal component 
C) Random component 
D) All of the above.

An annual time series cannot exhibit a seasonal component.

Model specification is the process of determining how well a forecasting model fits the past data.

A plot of the time series with time on the horizontal axis is an effective means of assessing whether the series is linear or nonlinear.

A time series is shown below.Perform single exponential smoothing for this data set using α = 0.2. What is the value of the forecast for period 6?

Which of the following time-series components can be identified when a company has 12 weeks of data beginning January and extending through March?

In a double smoothing model,large values for the two smoothing constants will result in greater smoothing of the time series.

One of the disadvantages of a regression-based linear trend forecasting model is that the forecast errors are computed for time periods that were used in developing the forecasting model and thus do not truly measure the forecasting ability of the model.

If the forecast errors are autocorrelated,this is a good indication that the model has been specified correctly.

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 value for the mean absolute deviation for months 1-12?

Which of the following is true about deseasonalizing data?

If the Durbin-Watson d statistic has a value close to 2,there is reason to believe that there is no autocorrelation between the forecast errors.

In a simple exponential smoothing model,which of the following statements is true?

The most useful tool to identify the trend component of a time series is

Which of the following time-series components is almost always present in sales data for electronics companies?

A time-series plot that exhibits a general increase in value from the early periods to the latest time periods:

The Boxer Company has been in business since 1998.The following sales data are recorded by quarter for the years 1999-2001. Which of the following time-series components are present in these data?

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

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Exam 16: Analyzing and Forecasting Time-Series Data

An annual time series cannot exhibit a seasonal component.

Model specification is the process of determining how well a forecasting model fits the past data.

A plot of the time series with time on the horizontal axis is an effective means of assessing whether the series is linear or nonlinear.

A time series is shown below.Perform single exponential smoothing for this data set using α = 0.2. What is the value of the forecast for period 6?

Which of the following time-series components can be identified when a company has 12 weeks of data beginning January and extending through March?

In a double smoothing model,large values for the two smoothing constants will result in greater smoothing of the time series.

One of the disadvantages of a regression-based linear trend forecasting model is that the forecast errors are computed for time periods that were used in developing the forecasting model and thus do not truly measure the forecasting ability of the model.

If the forecast errors are autocorrelated,this is a good indication that the model has been specified correctly.

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 value for the mean absolute deviation for months 1-12?

Which of the following is true about deseasonalizing data?

If the Durbin-Watson d statistic has a value close to 2,there is reason to believe that there is no autocorrelation between the forecast errors.

In a simple exponential smoothing model,which of the following statements is true?

The most useful tool to identify the trend component of a time series is

Which of the following time-series components is almost always present in sales data for electronics companies?

A time-series plot that exhibits a general increase in value from the early periods to the latest time periods:

The Boxer Company has been in business since 1998.The following sales data are recorded by quarter for the years 1999-2001. Which of the following time-series components are present in these data?

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