Question on: JAMB Mathematics - 2011
(\begin{array}{c|c}
Class Interval & 3 - 5 & 6 - 8 & 9 - 11 \ \hline Frequency & 2 & 2 & 2 \end{array}). Find the standard deviation of the above distribution.
A
√5
B
√6
C
√7
D
√2
Ask EduPadi AI for a detailed answer
Correct Option: B
(\begin{array}{c|c}Class Interval & 3 - 3 & 6 - 8 & 9 - 11 \ x & 4 & 7 & 10 \ f & 2 & 2 & 2 \ f - x & 8 & 14 & 20 \ |x - \bar{x}|^2 & 9 & 0 & 9 \ |x - \bar{x}|^2 & 18 0 & 18 \end{array})
(\bar{x}) = (\frac {\sum fx}{\sum f})
= (\frac {8 + 14 + 20}{2 + 2 + 2})
= (\frac{42}{6})
(\bar{x}) = 7
S.D = (\sqrt\frac{\sum f(x - \bar{x})^2}{\sum f})
= (\sqrt\frac{18 + 0 + 18}{6})
= (\sqrt\frac{36}{6})
= (\sqrt {6})
Add your answer
Please share this, thanks!
No responses