(begin{array}{c|c} class& 1 – 3 & 4 – 6 & 7 – 9\ hline Frequency & 5 & 8 & 5end{array})
Find the standard deviation of the data using the table above
Find the standard deviation of the data using the table above
-
A.
5 -
B.
(sqrt{6} -
C.
(frac{5}{3}) -
D.
(sqrt{5})
Correct Answer: Option A
Explanation
(begin{array}{c|c} text{class intervals} & Fre(F) & text{class-marks(x)} & Fx & (x – x)& (x – x)^2 & F(x – x)^2 \ hline 1 – 3 & 5 & 10 & 10 & -3 & 9 & 90\ 4 – 6 & 8 & 40 & 40 & 0 & 0 & 0 \ 7 – 9 & 5 & 40 & 40 & 3 & 9 & 360 \ hline & 18 & & 90 & & & 450 end{array})
x = (frac{sum fx}{sum f})
= (frac{90}{18})
= 5
S.D = (frac{sum f(x – x)^2}{sum f})
= (frac{450}{18})
= (sqrt{25})
= 5