r (m)	Electric field E (V/m)
1	52.8
2	13.3
3	5.93
4	3.37
5	2.15
6	1.49
7	1.10
8	0.84

The constant of proportionality k is called Coulomb's constant. In SI units, the constant k has the value k = 8.99 10⁹ Nm²/C².

Using the table above, make a scatter plot in Excel/Google Sheets/etc. of electric field E and distance r to determine Coulomb's constant k using the appropriate trendline.

Either make a graph and then create the appropriate trendline, or figure out how to make the graph into a straight line and then use a linear trendline. Once you have a trendline, compare the equation written above to the equation of the trendline to find k.

Insert the graph and write down the k value that you found.

k constant from trendline equation =?

Accepted value of k constant =?