bonjour
4.78 milliards = 4.78 x 10 ⁹
6.5 milliards = 6.5 x 10 ⁹
4.78 x 10 ⁹ : 6.5 x 10 ⁹
= 0.73538....x 10 ⁰
= ≅ 73.5 %
