Question 387261
If we use the first pair of data to get the slope of the line passing through them, then we would get {{{m = (30-20)/(10-5) = 10/5 = 2}}}.  If we use the first pair of x,y data, the point-slope form of the line would be y - 20= = 2(x-5), or y = 2x + 10, after simplifying.  Our linear equation would describe the first 4 pairs of data, but not the 5th and the 6th pairs.  Therefore the relationship is NOT linear.