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Swanage-Poole-Bournemouth Curve.pdf
Printable Forms

Here are links to the forms used in the examples


- prediction and
- interpolation forms

are useful for “real-life” work

These are “Pdf” files, so Adobe Reader is required - almost everyone has it.  If you don’t, it’s available as free download from Adobe.com

Curves and differences are for training purposes only and are not to be used for navigation


Here are links to the spreadsheets used to check interpolation in applying the rule of twelfths.  In order to use them you will need the appropriate software installed on your computer

Open Office is available as a free download from OpenOffice.org
Files open in new window
Link to MS Office 2007  Spreadsheet for Rule of Twefths
Link to MS Office 97 - 2003  Spreadsheet for Rule of Twefths
Link to Open Office Spreadsheet for Rule of Twefths