题目

已知回归直线方程为=0.50x-0.81，则x=25时，y的估计值为______________. 答案：思路分析:y的估计值就是当x=25时的函数值,即0.50x-0.81=11.69.答案：11.69The boy got lost after arguing with his parents.Which is correct for the underlined part?A. /?:/ B. /a:/ C. /?/ D. /?u/