在一元线性回归的数学模型中，其正规方程组为<img src="http://www.weimei168.com/uploads/202208/161223994043351.png" width="272" height="94" />已知<img src="http://www.weimei168.com/uploads/202208/161223994679891.png" width="25" height="40" />，则<img src="http://www.weimei168.com/uploads/202208/161223995179971.png" width="27" height="42" />=