Why is it appropriate to have the yintercept equal to zero w

Why is it appropriate to have the y-intercept equal to zero when fitting the data with the trendline?

Solution

A trendline is most reliable when its R-squared value is at or near 1. When you fit a trendline to your data, Graph automatically calculates its R-squared value. If you want, you can display this value on your chart.

you need to have the y-intercept equal to zero because you want to know the best fiting data in the trendline

to do that we need to make sure that we are doing with the lowest error possible

so we need to do y intercept equal to zero to be sure that we are not having a lot of error