化学兴趣小组的同学发现实验台上一瓶标签破损的无色溶液（标签如图）．他们提出可能是Na₂SO₄、NaHCO₃、Na₂CO₃溶液中的一种，于是决定对这瓶溶液进行实验探究．查阅资料：三种物质溶液在常温下的pH如下表

    Garbage collector Jose Gutierrez is 53 years old. When he was young his family was too poor to keep him in school. Jose left school when he was in Grade Two, but that did not stop him having a love for reading.

    Jose said he got the love of reading from his mother. “She read me stories every night,” said Jose. He hopes that every poor child in his city can have books to read. Jose started saving books from garbage twenty years ago. Every day he drives the garbage truck through the city's rich neighborhoods to get old books. Now there are about 20,000 books in Jose's small house. It is already a famous library.

    Books are rare things for children in poor neighborhoods. New books are too expensive. There are nineteen libraries in Bogota, the city where Jose lives, but they are all far from poor neighborhoods.

    Now Jose is famous in Bogota. Many people give old books to him. Jose plans to make more libraries to help more children.

根据短文内容，选择最佳答案。

（Ⅰ）求该作物的年收获量y关于它”相近“作物的株数x的线性回归方程；

（Ⅱ）农科所在如图所示的正方形地块的每个格点（指纵、横直线的交叉点）处都种了一株该作物，其中每一个小正方形的面积为1，若在所种作物中随机选取一株，求它的年收获量的分布列与数学期望．（注：年收获量以线性回归方程计算所得数据为依据）

附：对于一组数据（x₁，y₁），（x₂，y₂），…，（x_n，y_n），其回归直线y=a+bx的斜率和截距的最小二乘估计分别为 $\widehat{b}$ = $\frac{{{\displaystyle \sum }}_{i=1}^n\left(x_i-\overline{x}\right)\left(y_i-\overline{y}\right)}{{{\displaystyle \sum }}_{i=1}^n{(x_i-\overline{x})}^2}$ = $\frac{{{\displaystyle \sum }}_{i=1}^n{x}_i{y}_i-n\overline{x}\cdot \overline{y}}{{{\displaystyle \sum }}_{i=1}^n{x}_i{}^2-n\cdot {\overline{x}}^2}$ ， $\widehat{a}$ = $\overline{y}$ ﹣ $\widehat{b}\overline{x}$ ．