Find the standard deviation of the numbers 3,6,2,1,7 and 5.

  • A 2.00
  • B 2.16
  • C 2.50
  • D 2.56
waec 2011furthermathematics

The correct answer is B. 2.16

\(x\) 3 6 2 1 7 5 Total = 24
\(x - \bar{x}\) -1 2 -2 -3 3 1  
\((x - \bar{x})^{2}\) 1 4 4 9 9 1 28
\(\bar{x} = \frac{24}{6} = 4\) \(S.D = \sqrt{\frac{\sum (x - \bar{x})^{2}}{n}}\) = \(\sqrt{\frac{28}{6}} = \sqrt{4.667} = 2.16\) Previous question Next question