As I know, it is like this...
From the bottom point you have put, you connect it till the end point with just a straight line. You don't follow every points as that isn't line of best fit.
Hope that did help! :)
you draw the line of best fit
if you only have one point
yes
When points are marked on a graph, a line is often drawn across the dots plotted. A line of best fit is a straight line that goes through as many of such points as possible.
show a trend
You want to draw a line through your plotted points and try to get equal amounts on either side.
No. When you draw a best line of fit on the scattered plot, the line would not be straight.
You should use a curve if the scatter plot shows a clear curving shape. Otherwise draw a straight line. But a line of best fit should never zigzag from point to point.
The line of best fit does not have to start from 0.
Yes but phrased differently
Many sets of data do not form into straight lines. If by "What if" you mean how to plot a line onto this graph. Then simply draw a curved line of best fit.
The line that minimized the sum of the squares of the diffences of each point from the line is the line of best fit.