Đáp án `+` Giải thích các bước giải:

`a)` \begin{array}{|c|c|c|}\hline \text{Điểm (x)}&\text{3}&\text{4}&\text{5}&\text{6}&\text{7}&\text{8}&\text{9}&\text{10}&\text{}\\\hline \text{Tần số (n)}&\text{3}&\text{3}&\text{6}&\text{4}&\text{10}&\text{7}&\text{3}&\text{4}&\text{N=40}\\\hline\end{array}

`-` Mốt của dấu hiện là `M_0=7` `(` với tần số là `10)` 

`b)` $X=\dfrac{3.3+4.3+5.6+6.4+7.10+8.7+9.3+10.4}{40}=6,7(điểm)$ 

`a)`\begin{array}{|c|c|c|}\hline \text{Giá trị (x)}&\text{Tần số(n)}&\text{}\\\hline \text{3}&\text{3}&\text{}\\\hline \text{4}&\text{3}&\text{}\\\hline \text{5}&\text{6}&\text{}\\\hline \text{6}&\text{4}&\text{}\text{}&\text{}&\text{}\\\hline \text{7}&\text{10}&\text{}\\\hline \text{8}&\text{7}&\text{}\\\hline \text{9}&\text{3}&\text{}\\\hline \text{10}&\text{4}&\text{N=40}\\\hline\end{array}

`M_o=7`

`b)``\overline{X}=`$\dfrac{3.3+4.3+5.6+6.4+7.10+8.7+9.3+10.4}{40}$

`\overline{X}=6,7`