Albert is studying Coulomb's inverse-square law, he simplifies it to the following equation:

�
=
�
�
r=
F
K
​

​

He needs to calculate the value of r with the following data:

K = 5.48 correct to 2 decimal places

F = 4.726 correct to 3 decimal places

By considering bounds, work out the value of r to a suitable degree of accuracy.