excel trendline formula is inaccurate

While trying to create a graph with trendline to predict what a thermistor reading for a Prius’s radiator/engine temperature would be at certain temperatures I started battling MSFT’s Excel.

I created a chart with the known data collected about the voltage at the thermistor for a list of temperatures. I wanted a trendline to show the calculation so that I could use it to calculate the resistance of the thermistor at those temperatures. However, after creating a chart and looking at the trendline formula’s calculation of known data, something was completely screwed up.

After some Google searches there was a link to Microsoft’s Help and Support website that indicated that

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