I will assume that "made a line of best fit" means you added a
trendline. If so, double-click the trendline. In the resulting dialog
box, from the Options tab, check 'Set Intercept to' and enter zero in
the adjacent textbox.

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Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
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In article ,
says...
I made a scatter graph, with the origin value at 0. when i made a line of
best fit, the line starts and 1. how do i make it start at 0??