Data Analysis with Microsoft Excel: Updated for Office 2007

448 Statistical Methods Taking the fi ve-year moving average smoothes out the data a bit; however, even the smoothed values show ...

Chapter 11 Times Series 449 an approach that gives equal weight to all observations within the period is not always reasonable. ...

450 Statistical Methods Forecasting with Exponential Smoothing Exponential smoothing is often used to forecast the value of the ...

Chapter 11 Times Series 451 The square root of the MSE gives us the standard error, which indicates the magnitude of the typical ...

452 Statistical Methods This worksheet shows the observed percentage changes in a sample time series overlaid with the one-param ...

Chapter 11 Times Series 453 To decrease the value of the smoothing constant: 1 Click the down spin button repeatedly to reduce t ...

454 Statistical Methods To increase the smoothing factor: 1 Click the up spin button repeatedly to increase the value of w to 0. ...

Chapter 11 Times Series 455 Choosing a Value for w As you saw in the Exponential Smoothing workbook, you have to choose the valu ...

456 Statistical Methods Figure 11-15 The Perform Exponential Smoothing dialog box 6 Click OK. Excel displays the worksheet shown ...

Chapter 11 Times Series 457 The output shown in Figure 11-16 consists of three columns: the observa- tion numbers, the recorded ...

458 Statistical Methods average yield would be the weather, because a region of the country might go through several years of dr ...

Chapter 11 Times Series 459 CONCEPT TUTORIALS Smoothing Three-Parameter Exponential The Exponential Smoothing workbook that you ...

460 Statistical Methods The values chosen for w and t are important in determining what the forecasted value for the time series ...

Chapter 11 Times Series 461 With a higher smoothing constant, the forecasted trend of the time series shows an increase of 0.044 ...

462 Statistical Methods 4 Click the Linear Trend option button to add a linear trend to the forecasted temperature values. 5 Cli ...

Chapter 11 Times Series 463 difference of the values or the ratio? In many cases seasonal changes are best expressed in ratios, ...

464 Statistical Methods Additive Seasonality Sometimes the seasonal variation is expressed in additive terms, especially if ther ...

Chapter 11 Times Series 465 To open the Liquor workbook: 1 Open the Liquor workbook from the Chapter11 data folder. 2 Save the w ...

466 Statistical Methods 5 Within the Format Axis dialog box, click the Specify interval unit option button and enter 24 for the ...

Chapter 11 Times Series 467 The plot shows that production is seasonal, with peaks occurring each winter (around the holidays). ...