Statistics And Probability Question 120
Question: The S.D. of 5 scores 1, 2, 3, 4, 5 is
[AMU 1991; DCE 2000]
Options:
A) $ \frac{2}{5} $
B) $ \frac{3}{5} $
C) $ \sqrt{2} $
D) $ \sqrt{3} $
Show Answer
Answer:
Correct Answer: C
Solution:
Mean $ \bar{x}=\frac{1+2+3+4+5}{5}=3 $ S.D.= $ \sigma $ = $ \sqrt{\frac{1}{n}\sum{x_i^{2}-(\bar{x}}{{)}^{2}}} $ = $ \sqrt{\frac{1}{5}(1+4+9+16+25)-9} $ = $ \sqrt{11-9}=\sqrt{2} $ .
BETA
