Exam 6: Times Series Analysis and Forecasting

Describe a time series plot and discuss its purpose and when in the forecasting process it should be constructed.

Explain and contrast three measures of forecast accuracy.

Smoothing methods are more appropriate for a stable time series than when significant trend or seasonal patterns are present.

A customer comment phone line is staffed from 8:00 a.Develop the optimization model that finds the estimated regression equation that minimize the sum of squared error. a.m. to 4:30 p.m. five days a week. Records are available that show the number of calls received every day for the last five weeks. Week Day Number Week Day Number 1 28 4 27 12 13 16 W 16 15 18 23 24 2 25 5 26 10 11 14 18 14 17 26 25 3 32 15 15 13 21 b.Solve for the estimated regression equation. c.Forecast the five days of week 6.

Seasonal patterns

One measure of the accuracy of a forecasting model is the

All of the following are true about a stationary time series except

Which of the following forecasting methods puts the least weight on the most recent time series value?

Time series methods base forecasts only on past values of the variables.

The average SAT verbal score for students from one high school over the last ten exams is 508,490,502,505,493,506,492,490,503,501 Do the scores support an increasing or a decreasing trend?

If data for a time series analysis is collected on an annual basis only,which pattern does not need to be considered?

Sales (in thousands)of the new Thorton Model 506 convection oven over the eight-week period since its introduction have been as follows: Week Sales 1 18.6 2 21.4 3 25.2 4 22.4 5 24.6 6 19.2 7 21.7 8 23.8 a.Which exponential smoothing model provides better forecasts, one using  = .6 or  = .2? Compare them using mean squared error. b.Using the two forecast models in part (a), what are the forecasts for week 9?

All of the following are true about a cyclical pattern except

Explain what conditions make quantitative forecasting methods appropriate.

The number of cans of soft drinks sold in a machine each week is recorded below.Develop forecasts using a three-period moving average. 338,219,278,265,314,323,299,259,287,302

All of the following are true about qualitative forecasting methods except

A hospital records the number of floral deliveries its patients receive each day.For a two-week period,the records show 15,27,26,24,18,21,26,19,15,28,25,26,17,23 Use exponential smoothing with a smoothing constant of .4 to forecast the number of deliveries.

If the random variability in a time series is great and exponential smoothing is being used to forecast,then a high alpha ()value should be used.

If the random variability in a time series is great,a high  value should be used to exponentially smooth out the fluctuations.

Quarterly revenues (in $1,000,000's)for a national restaurant chain for a five-year period were as follows: Quarter Year 1 Year 2 Year 3 Year 4 Year 5 1 33 42 54 70 85 2 36 40 53 67 82 3 35 42 54 70 87 4 38 47 62 77 99 a.Solve for the forecast equation that minimizes the sum of squared error. b.Forecast the four quarters of year 6.