If $u_{i}=\frac{x_{i}-25}{10}, \Sigma f_{i} u_{i}=20, \Sigma f_{i}=100$, then $\bar{x}=$

[question] Question. If $u_{i}=\frac{x_{i}-25}{10}, \Sigma f_{i} u_{i}=20, \Sigma f_{i}=100$, then $\bar{x}=$ (a) 23 (b) 24 (c) 27 (d) 25 [/question] [solution] solution: Given: $u_{i}=\frac{x_{i}-25}{10}, \Sigma f_{i} u_{i}=20$ and $\Sigma f_{i}=100$ Now, $u_{i}=\frac{x_{i}-A}{h}=\frac{x_{i}-25}{10}$ Therefore, $h=10$ and $A=25$ We know that $\bar{x}=A+h\left\{\frac{1}{N} \sum f_{i} u_{i}\right\}$ $=25+10\left\{\frac{1}{100} \times 20\right\}$ $=25+10 \times \frac{1}{5}$ $=25+2$ $\bar{x}=27$ He...