title: LINEST gives #VALUE! error for some data
body: <p>I'm wondering if anyone has any tips for using LINEST in Excel (2010). It's easy to find guides but difficult to get help troubleshooting. This may not be exactly the right forum but everyone's so helpful around here I can't resist asking.</p>
  
  <p>I'm trying to use the Excel LINEST function to fit a third-order polynomial to a set of data.</p>
  
  <p><code>
  X_List: 44.00   45.50   46.30   46.80   47.50   47.90   48.60   49.90   51.20   51.80   52.30   53.00   53.40   54.30   55.70</p>
  
  <p>Y_List: 0.10    1.00    3.00    5.00    10.00   15.00   25.00   50.00   75.00   85.00   90.00   95.00   97.00   99.00   99.90
  </code></p>
  
  <p>The LINEST equation I'm using is: <code>=LINEST(Y_LIST, X_LIST^{1,2,3})</code></p>
  
  <p>This invariably gives me a #VALUE! error when I use <code>^{1,2,3}</code> or <code>^{1,2}</code> but not <code>^{1}</code>. This same formula works with another data set so I know it's not a typo issue, and when I make a chart of the data and apply a trendline, it gives me a formula, so it should be able to calculate <em>something</em>. It does this regardless of whether or not I use the "array" entry method, i.e. ctrl-shift-enter with a selected range.</p>
  
  <p>I figure either there's some problem with my numbers that I don't understand, or possibly that the syntax has changed from Excel 2007 such that the <code>^{1,2,3}</code> bit no longer works the way I expect.</p>