Dear friend,

    My name is Erick. I am 12. My birthday is on October 12 th. I am from America. I'm in Class 3, Grade 7. We are learning Chinese in our school. Our Chinese teacher's name is Wang Hao.

    Here are some of my friends. Jimmy is tall and he has black hair. He is good at playing basketball. He is a member of the Basketball Club. May is short and she wears glasses and a yellow dress. She likes English very much and speaks English very well. Sally is a black girl. She has short hair. She likes swimming. She swims best in the swimming team. I like music. I'm the boy with glasses.

Yours,

Erick

为了判断喜欢语文学科是否与性别有关系，根据表中的数据，得到K²的观测值k= $\frac{50\times \left(13\times 20-10\times 7\right)2}{23\times 27\times 20\times 30}$ ≈4.844，因为k≥3.841，根据下表中的参考数据：

判定喜欢语文学科与性别有关系，那么这种判断出错的可能性为（   ）

如图，在矩形ABCD中，AB=5，BC=6，点E，F，G，H分别在已知矩形的四条边上，且四边形EFGH也是矩形，GF=2EF．若设AE=a，AF=b，则a与b满足的关系为（　　）