Statistics And Probability Question 411
Question: The mean and S.D. of 1, 2, 3, 4, 5, 6 is
Options:
A) $ \frac{7}{2},,\sqrt{\frac{35}{12}} $
B) 3, 3
C) $ \frac{7}{2},,\sqrt{3} $
D) $ 3,,\frac{35}{12} $
Show Answer
Answer:
Correct Answer: A
Solution:
Mean $ \bar{x}=\frac{1+2+3+4+5+6}{6} $ $ =\frac{21}{6}=\frac{7}{2} $ S.D. $ =\sigma =\sqrt{\frac{1}{n}\Sigma x_i^{2}-{{(\bar{x})}^{2}}} $ $ =\sqrt{\frac{1}{6}(1+4+9+16+25+36)-\frac{49}{4}} $ $ =\sqrt{\frac{91}{6}-\frac{49}{4}} $ $ =\sqrt{\frac{182-147}{12}} $ $ =\sqrt{\frac{35}{12}} $ .
BETA
