Question

the best paper was wrongly scored 75 instead of 85 what will be the new mean if the average score of 24 students in a class in 58 marks

Answer 1

$\text{An incorrect old average score:}$

$\bar{x_{1}}=\frac{1}{n}\Sigma_{i=1}^nx_i;n=24$

$\bar{x_{1}}=\frac{1}{24}\Sigma_{i=1}^{24}x_i=58;$

$\text{The correct average score:}$

$\bar{x}=\frac{1}{24}(\Sigma_{i=1}^{24}x_i+10)=58+\frac{10}{24}\approx58.42$

Answer: 58.42 is a new average score.