Exam 18: Forecasting

A method of smoothing a time series that can be used to identify the combined trend/cyclical component is

The time series component that reflects gradual variability over a long time period is called

The following linear trend expression was estimated using a time series with 17 time periods. T_t = 129.2 + 3.8t The trend projection for time period 18 is

The sales records of a major auto manufacturer over the past ten years are shown below. Develop a linear trend expression and project the sales (the number of cars sold)for time period t = 11.

Exhibit 18-2 Consider the following time series. -Refer to Exhibit 18-2.The forecast for period 10 is

The sales volumes of CMM,Inc. ,a computer firm,for the past 8 years is given below. a.Develop a linear trend expression for the above time series. b.Forecast sales for period 9.

What is the forecast for July based on a three-month weighted moving average applied to the following past demand data and using the weights: 5,4,and 3 (largest weight is for most recent data)? Show all of your computations for April through July.

Exhibit 18-2 Consider the following time series. -Refer to Exhibit 18-2.The slope of linear trend equation,b₁,is

Actual sales for January through April are shown below. Use exponential smoothing with = 0.2 to calculate smoothed averages and forecast sales for May from the above data.Assume the forecast for the initial period (January)is 18.Show all of your computations.

Demand for a product and the forecasting department's forecast (naïve model)for a product are shown below. a.Compute the mean absolute error. b.Compute the mean squared error.

Below you are given the seasonal factors and the estimated trend equation for a time series.These values were computed on the basis of 5 years of quarterly data. T = 126.23 - 1.6t Produce forecasts for all four quarters of year 6 by using the seasonal and trend components.

John has collected the following information on the amount of tips he has collected from parking cars the last seven nights. a.Compute the 3-day moving averages for the time series. b.Compute the mean square error for the forecasts. c.Compute the mean absolute deviation for the forecasts. d.Forecast John's tips for day 7.

Exhibit 18-3 Consider the following time series. -Refer to Exhibit 18-3.In which time period does the value of Y_i reach zero?

Below you are given the first four values of a time series. Using a 4-period moving average,the forecasted value for period 5 is

You are given the following information on the quarterly profits for Ajax Corporation. a.Find the four-quarter centered moving averages. b.Compute the seasonal-irregular component. c.Compute the seasonal factors for all four quarters. d.Represent the deseasonalized series.

The time series component that reflects variability during a single year is called

The yearly series below exhibits a long-term trend.Use the appropriate forecasting technique to produce forecasts for years 11 and 12.

What is the forecast for July based on a three-month weighted moving average applied to the following past demand data and using the weights: 5,3,and 2 (largest weight is for most recent data)? Show all of your computations for April through July.

If the estimate of the trend component is 158.2,the estimate of the seasonal component is 94%,the estimate of the cyclical component is 105%,and the estimate of the irregular component is 98%,then the multiplicative model will produce a forecast of

Which of the following smoothing constants would make an exponential smoothing forecast equivalent to a naive forecast?