Question

a class measured the radius and circumference of various circular objects the results are plotted on the graph. Does does there appear to be a proportional relationship between the radius and circumference of a circle explain or show your reasoning why might the measure radius and circumference is not be exactly proportional?

Answer 1

If we construct the straight line from the origin, we can see a proportinal relatioship between the radius and the circumference, however , I have observed that the kids left an empty space between 4 and 6 that is unaccounted for ,

Secondly, moving from point (3;18) and (4;25), our slope is

m = (25-28)/)4-3) = 7

and moving from point ( 6;38) and (7;44) ; our slope is

m = ( 44-38) / ( 7-6 ) = 6/1 = 6

between this 2 points , we can cleary see that our slopes are different; this is an indication that they are not exactly proportional.