Let x be the length of the shadow of the 3m tall tether ball pole, and y be the length of the shadow of the 6.8m tall flagpole. Then, we know that:
x / 3 = y / 6.8
We can solve for y by multiplying both sides by 6.8:
y = (6.8 / 3) * x
y = 2.27x
So, the length of the shadow of the 6.8m flagpole is 2.27 times the length of the shadow of the 3m tether ball pole.
Therefore, any answer choice that is 2.27 times the length of the shadow of the 3m tether ball pole could be the length of the shadow of the 6.8m flagpole.