According to the formula f=se(r-d)t, where e is followed by the superscript of e.

Three months later, the standard & poor's futures price =1000e (10%-5%) 3/12 =10/2.578.

After three months, the spot point of the index is 1 100, so1100-1000 =100;

Futures price difference,1012.578-950 = 62.578;

Arbitrage, buy spot, sell futures. Total profit = 100-62.578=37.422