2025年高三年级第三次适应性检测
数学参考答案及评分标准
一、单项选择题：本题共8小题，每小题5分，共40分．
1--8：DABCCACA
二、多项选择题：本题共3小题，每小题6分，共18分．
9．BD10．ACD11．BCD
三、填空题：本题共3个小题，每小题5分，共15分．
573100
12．；13．；14．5
84
四、解答题：本题共5小题，共77分．解答应写出文字说明，证明过程或演算步骤．
15．（13分）
解：(1)销售额不少于万元的有天，的所有可能取值为1,2,3························1分
603X
1123
C3CC3C1
P(X1)3,P(X2)23,P(X3)3······················4分
C310C35C310
555
所以的分布列为：
X
X123
331
P
10510
3319
所以E(X)1??2??3?································································6分
105105
11
(2)，，·······················7分
x（2?4?5?6?8）5y（20?30?60?60?80）50
55
5
?xy2?20?4?30?5?60?6?60?8?801460··········································8分
ii
i1
5
22····································9分
?x?5xi4?16?25?36?64?5?25145?12520
i1
?1460?5?5?50??
b10.5，ay?bx50?10.5?5?2.5······························11分
20
所以经验回归方程为y10.5x?2.5?，·······················