Exam 15: Multiple Regression and Model Building

arrow
  • Select Tags
search iconSearch Question
flashcardsStudy Flashcards
  • Select Tags

The recurring up-and-down movement of a time series around trend levels that last more than one calendar year is called ____________.

(Multiple Choice)
4.8/5
(38)

A _______________ index is most useful if the base quantities provide a reasonable representation of consumption patterns in succeeding time periods.

(Multiple Choice)
4.7/5
(31)

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

(Essay)
4.8/5
(27)

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: trt = 12 + 2t.Use this equation to forecast the demand for this product,and then calculate the MSD.

(Multiple Choice)
4.9/5
(38)

Box-Jenkins methodology is a more sophisticated approach to forecasting a time series with components that might be changing over time.

(True/False)
4.8/5
(31)

Forecasters using a multiplicative decomposition model or time series regression model,assume that the time series components are changing over time.

(True/False)
4.8/5
(41)

A time series decomposition method would not be used to forecast seasonal data.

(True/False)
4.9/5
(36)

Causal variables can be used in forecasting models.

(True/False)
4.9/5
(35)

Consider a time series with 15 quarterly sales observations.Using the quadratic trend model,the following partial computer output was obtained. Consider a time series with 15 quarterly sales observations.Using the quadratic trend model,the following partial computer output was obtained.   Test the significance of the t<sup>2</sup> term at α =.05.State the critical T value (rejection point)and the p-value.Make your decision using a two-sided null hypothesis. Test the significance of the t2 term at α =.05.State the critical T value (rejection point)and the p-value.Make your decision using a two-sided null hypothesis.

(Essay)
4.9/5
(33)

The Durbin-Watson statistic is used to detect _____________.

(Multiple Choice)
4.8/5
(39)

Exponential smoothing is a forecasting method that applies equal weights to the time series observations.

(True/False)
4.8/5
(36)

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

(Essay)
4.8/5
(39)

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

(Multiple Choice)
4.9/5
(44)

Dummy variables are used to model increasing seasonal variation.

(True/False)
4.7/5
(40)

Consider the following set of quarterly sales data,given in thousands of dollars. Consider the following set of quarterly sales data,given in thousands of dollars.   The following dummy variable model that incorporates a linear trend and constant seasonal variation was used: y(t)= B<sub>0</sub> + B<sub>1</sub><sub>t</sub> + B<sub>Q1</sub>(Q1)+ B<sub>Q2</sub>(Q2)+ B<sub>Q3</sub>(Q3)+ E<sub>t</sub>.In this model,there are 3 binary seasonal variables (Q1,Q2,and Q3),where Qi is a binary (0,1)variable defined as: Qi = 1,if the time series data is associated with quarter i; Qi = 0,if the time series data is not associated with quarter i.The results associated with this data and model are given in the following Minitab computer output.The regression equation is Sales = 2442 + 6.2 Time − 693 Q1 − 1499 Q2 + 153 Q3   Provide a managerial interpretation of the regression coefficient for the variable time. The following dummy variable model that incorporates a linear trend and constant seasonal variation was used: y(t)= B0 + B1t + BQ1(Q1)+ BQ2(Q2)+ BQ3(Q3)+ Et.In this model,there are 3 binary seasonal variables (Q1,Q2,and Q3),where Qi is a binary (0,1)variable defined as: Qi = 1,if the time series data is associated with quarter i; Qi = 0,if the time series data is not associated with quarter i.The results associated with this data and model are given in the following Minitab computer output.The regression equation is Sales = 2442 + 6.2 Time − 693 Q1 − 1499 Q2 + 153 Q3 Consider the following set of quarterly sales data,given in thousands of dollars.   The following dummy variable model that incorporates a linear trend and constant seasonal variation was used: y(t)= B<sub>0</sub> + B<sub>1</sub><sub>t</sub> + B<sub>Q1</sub>(Q1)+ B<sub>Q2</sub>(Q2)+ B<sub>Q3</sub>(Q3)+ E<sub>t</sub>.In this model,there are 3 binary seasonal variables (Q1,Q2,and Q3),where Qi is a binary (0,1)variable defined as: Qi = 1,if the time series data is associated with quarter i; Qi = 0,if the time series data is not associated with quarter i.The results associated with this data and model are given in the following Minitab computer output.The regression equation is Sales = 2442 + 6.2 Time − 693 Q1 − 1499 Q2 + 153 Q3   Provide a managerial interpretation of the regression coefficient for the variable time. Provide a managerial interpretation of the regression coefficient for the variable "time."

(Essay)
4.7/5
(33)

A univariate time-series model is used to predict future values of a time series based only upon past values of a time series.

(True/False)
4.9/5
(31)

When deseasonalizing a time series observation,we divide the actual time series observation by its ___________.

(Multiple Choice)
4.9/5
(42)

A positive autocorrelation implies that negative error terms will be followed by negative error terms.

(True/False)
4.9/5
(33)

A simple exponential forecasting method would not be used to forecast seasonal data.

(True/False)
4.9/5
(33)

Cyclical variation exists when the magnitude of the seasonal swing does not depend on the level of a time series.

(True/False)
4.7/5
(32)
Showing 61 - 80 of 119
close modal

Filters

  • Essay(0)
  • Multiple Choice(0)
  • Short Answer(0)
  • True False(0)
  • Matching(0)