√m/3 = 4
To remove the radical sign, square both sides.
(√m/3)² = 4²
m/3 = 16
To remove the denominator of 3, multiply both sides by 3.
3 (m/3) = 3(16)
m = 48
To check: Substitute m by its value.
√m/3 = 4
√48/3 = 4
√16 = 4
4 = 4
Fourth test mark should be 86
85 + 82 + 75 + 86 = 328
328 divide by 4 (as there are four tests) = 82
I do not really understand the question clarify is it 256 times 3/4 if that is the question none of the above is right.<span />