Exam 16: Time-Series Forecasting

A second-order autoregressive model for average mortgage rate is: If the average mortgage rate in 2012 was 7.0, and in 2011 was 6.4, the forecast for 2014 is __________.

Each forecast using the method of exponential smoothing depends on all the previous observations in the time series.

SCENARIO 16-13 Given below is the monthly time series data for U.S.retail sales of building materials over a specific year. The results of the linear trend, quadratic trend, exponential trend, first-order autoregressive, second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the month is 0: Below is the residual plot of the various models: -Referring to Scenario 16-13, what is the p-value for the t test statistic for testing the significance of the quadratic term in the quadratic-trend model?

SCENARIO 16-12 A local store developed a multiplicative time-series model to forecast its revenues in future quarters, using quarterly data on its revenues during the 5-year period from 2009 to 2013.The following is the resulting regression equation: where is the estimated number of contracts in a quarter. X is the coded quarterly value with X = 0 in the first quarter of 2008. is a dummy variable equal to 1 in the first quarter of a year and 0 otherwise. is a dummy variable equal to 1 in the second quarter of a year and 0 otherwise. is a dummy variable equal to 1 in the third quarter of a year and 0 otherwise. -Referring to Scenario 16-12, the best interpretation of the coefficient of in the regression equation is:

When using the exponentially weighted moving average for purposes of forecasting rather than smoothing,

SCENARIO 16-14 A contractor developed a multiplicative time-series model to forecast the number of contracts in future quarters, using quarterly data on number of contracts during the 3-year period from 2011 to 2013.The following is the resulting regression equation: where is the estimated number of contracts in a quarter. X is the coded quarterly value with X = 0 in the first quarter of 2011. is a dummy variable equal to 1 in the first quarter of a year and 0 otherwise. Q is a dummy variable equal to 1 in the second quarter of a year and 0 otherwise. is a dummy variable equal to 1 in the third quarter of a year and 0 otherwise. -Referring to Scenario 16-14, in testing the coefficient of X in the regression equation (0.117)the results were a t-statistic of 9.08 and an associated p-value of 0.0000.Which of the following is the best interpretation of this result?

The cyclical component of a time series

The MAD is a measure of the mean of the absolute values of the deviations between the actual and the fitted values in a given time series.

SCENARIO 16-3 The following table contains the number of complaints received in a department store for the first 6 months of last year. -Referring to Scenario 16-3, if this series is smoothed using exponential smoothing with a smoothing constant of 1/3, how many values would it have?

The following is the list of MAD statistics for each of the models you have estimated from time-series data: Based on the MAD criterion, the most appropriate model is

SCENARIO 16-5 The number of passengers arriving at San Francisco on the Amtrak cross-country express on 6 successive Mondays were: 60, 72, 96, 84, 36, and 48. -Referring to Scenario 16-5, the number of arrivals will be exponentially smoothed with a smoothing constant of 0.25.The smoothed value for the third Monday will be __________.

SCENARIO 16-8 The manager of a marketing consulting firm has been examining his company's yearly profits. He believes that these profits have been showing a quadratic trend since 1994.He uses Microsoft Excel to obtain the partial output below.The dependent variable is profit (in thousands of dollars), while the independent variables are coded years and squared of coded years, where 1994 is coded as 0, 1995 is coded as 1, etc. SUMMARY OUTPUT -Referring to Scenario 16-8, the fitted value for 1994 is __________.

SCENARIO 16-6 The president of a chain of department stores believes that her stores' total sales have been showing a linear trend since 1993.She uses Microsoft Excel to obtain the partial output below. The dependent variable is sales (in millions of dollars), while the independent variable is coded years, where 1993 is coded as 0, 1994 is coded as 1, etc. SUMMARY OUTPUT -Referring to Scenario 16-6, the forecast for sales (in millions of dollars)in 2015 is __________.

After estimating a trend model for annual time-series data, you obtain the following residual plot against time, the problem with your model is that

SCENARIO 16-13 Given below is the monthly time series data for U.S.retail sales of building materials over a specific year. The results of the linear trend, quadratic trend, exponential trend, first-order autoregressive, second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the month is 0: Below is the residual plot of the various models: -Referring to Scenario 16-13, what is your forecast for the month using the first-order autoregressive model?

SCENARIO 16-11 The manager of a health club has recorded mean attendance in newly introduced step classes over the last 15 months: 32.1, 39.5, 40.3, 46.0, 65.2, 73.1, 83.7, 106.8, 118.0, 133.1, 163.3, 182.8, 205.6, 249.1, and 263.5.She then used Microsoft Excel to obtain the following partial output for both a first- and second-order autoregressive model. SUMMARY OUTPUT - Order Model SUMMARY OUTPUT - 1 Order Model -Referring to Scenario 16-11, using the first-order model, the forecast of mean attendance for month 16 is __________.

SCENARIO 16-13 Given below is the monthly time series data for U.S.retail sales of building materials over a specific year. The results of the linear trend, quadratic trend, exponential trend, first-order autoregressive, second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the month is 0: Below is the residual plot of the various models: -Referring to Scenario 16-13, what is the exponentially smoothed value for the 1 month using a smoothing coefficient of W = 0.25 if the exponentially smoothed value for the 1 and month are 9,477.7776 and 9,411.8332, respectively?

SCENARIO 16-13 Given below is the monthly time series data for U.S.retail sales of building materials over a specific year. The results of the linear trend, quadratic trend, exponential trend, first-order autoregressive, second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the month is 0: Below is the residual plot of the various models: -Referring to Scenario 16-13, the best autoregressive model using the 5% level of significance is

SCENARIO 16-13 Given below is the monthly time series data for U.S.retail sales of building materials over a specific year. The results of the linear trend, quadratic trend, exponential trend, first-order autoregressive, second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the month is 0: Below is the residual plot of the various models: -Referring to Scenario 16-13, what is your forecast for the 13th month using the exponential- trend model?

SCENARIO 16-13 Given below is the monthly time series data for U.S.retail sales of building materials over a specific year. The results of the linear trend, quadratic trend, exponential trend, first-order autoregressive, second-order autoregressive and third-order autoregressive model are presented below in which the coded month for the month is 0: Below is the residual plot of the various models: -Referring to Scenario 16-13, what is the value of the t test statistic for testing the significance of the quadratic term in the quadratic-trend model?