The range is: [26.86-0.02, 26.86+0.02] = [26.84, 26.88]
Answer:

Explanation:
The expression for the electric force between two charges

where K is the Coulomb's constant (k=9*10^{9}Nm^2/C^2), and we have that
q1=q
q2=3q
r=3.39m
F=2.4*10^{-6}N
By replacing in the formula we have

and by taking apart q we have

hope this helps!!
A physical quantity is a property of a material or system that can be quantified by measurement. A physical quantity can be expressed as the combination of a numerical value and a unit. For example, the physical quantity mass can be quantified as n kg, where n is the numerical value and kg is the unit.