# Data analysis 1, linear relations, Zooming in, but not through the origin

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This is continuing the analysis of the data the Excel file analysis1 V2, in the leaf The Data, 2 that we started to analyse in the previous page.

How about if we do not know it goes through the origin? We can then add points to the last column: The values were chosen to make the slope as small or big as possible. The plot would now look like: The slopes are 0.137 and 0.106. That gives us  0±0.2. The “y”-intercepts are 0.046 and –0.097, that gives us –0.03±0.08.

This will finally give us

R=(1.4±0.2)L –0.03±0.08

The difference between the two cases, the previous analysis and this one,  is if you can assume it is a proportionality (goes through the origin) or not.

As you can see the result from this analysis is consistent with the result from the previous one, R=(1.41±0.05)L. The value zero is in the range –0.03±0.08, and 1.41±0.05 is within the range 1.4±0.2. Up a level : IB Physics
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Next page : Data analysis, part 2, more linear Data Last modified: Jan 7, 2017 @ 15:06