I have a question about the 'best-fit' line on a graph. Usually, in my physics lab, we did experiment, then plot the points on a graph. After that, my teacher would let us draw a best-fit line. However, we didn't connect the points to make this best-fit line since my teacher said many times that drawing a best-fit line doesn't mean to connect the points but go between these points. But sometimes how can you figure out this is a straight line or a curve (parabola)? How can you find the slope since you don't know which two points are actually on the line? However, when I took a physics exam, the question let me plot the points given on the table, then I did. Next, let me draw a best-fit line, so I drew a line that kind of go between the points, however, I saw other people draw a line that connecting these points, half a parabola. And It was correct. so I must be wrong. I am so confused with the best-fit line. Hope you can help.