Answer
1.9163715 metre of more ribbon is needed, which is equal to 6.28730807087 ft.
Work Step by Step
Circumference of the Earth is $2×\pi×(6.38 × 10^{6}m)$. Which is equal to 40 086 722.26 metres.
The circumference of the Earth when 1ft(0.305m) is added to the radius is $2×\pi×((6.38 × 10^{6}m) + 0.305m)$. Which is equal to 40 086 724.18 metres.
Therefore, the difference is the additional ribbon reqiured, which is $ 40 086 724.18m - 40 086 722.26m =1.9163715m$. Which is equal to 6.28730807087 ft.