XL98: Chart Polynomial Trendline Formula Is Inaccurate

ID: Q184789


The information in this article applies to:
  • Microsoft Excel 98 Macintosh Edition


SYMPTOMS

The equation that is displayed for a polynomial trendline on an xy (scatter) chart may be incorrect. When you manually substitute values for the x variable, Microsoft Excel 98 Macintosh Edition plots the trendline incorrectly.


CAUSE

Microsoft Excel 98 plots polynomial trendlines correctly; however, this problem occurs when you manually type x values. For appearance, each x value is rounded by the number of significant digits that are displayed in the chart. This allows the equation to occupy less space in the chart area. However, the accuracy of the equation is significantly reduced, which may cause a trend to appear to be incorrect.


WORKAROUND

To work around this behavior, increase the digits in the trendline equation by increasing the number of decimal places that are displayed. To do this, follow these steps:

  1. In the chart, select the trendline equation.


  2. On the Format menu, click Selected Data Labels.


  3. Click the Number tab, and click Number in the Category List.


  4. Increase the number of Decimal places to 8.


  5. Click OK.



STATUS

This behavior is by design of Microsoft Excel 98.

Additional query words: XL98 match different

Keywords : kbualink97 kbdta kbchart xlformula
Version : MACINTOSH:98
Platform : MACINTOSH
Issue type : kbprb


Last Reviewed: January 13, 2000
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