This STEM activity provide students with the learning experience of finding the relationship between two variables given a small set of data and then using the relationship to predict other values.
They manually attempt to fit a line through the data points plotted on a cartesian coordinate graph such that it a line of best fit, ie. where the sum of squares of the vertical distances of the points from the best fit line is minimized. This means that this points on this line will have the least possible error or deviation from the actual values.
This best fit line is then used to predict the values of one variable (as output) given the other variable (as input).