The contingency table is supplemented as follows:-(6 points).
Love mathematics, don't like mathematics, total boys 20 5 25 girls 10 15 25, total 30 20 50 (2) ∵ K2 = n (ad? BC)2(a+b)(c+d)(a+c)(b+d)= 50×(20× 15？ 10× 5) 230× 20× 25× 25 ≈ 8.333-(12 points)
∵8.333>7.879,
∴ 99.5% .............................. believed that playing basketball was related to sex (14).