It is estimated that the median score of female students in this mock exam is117;
(2) According to the stem leaf diagram, we can get a 2×2 contingency table. The total number of boys with excellent grades? 20 5? ? 25 girls? 15 ? 10 ? A total of 25? 35 ? 15 ? 50k 2 = 50(20× 10- 15×5)2÷(25×25×35× 15)≈2.38 1 > 2.072，
85% determined that excellent grades were related to gender.