Calculate the standard deviation of 30, 29, 25, 28, 32 and 24.
-
A.
2.0 -
B.
2.8 -
C.
3.0 -
D.
3.2
Correct Answer: Option B
Explanation
| (x) | (x – mu) | ((x – mu)^{2}) |
| 24 | -4 | 16 |
| 25 | -3 | 9 |
| 28 | 0 | 0 |
| 29 | 1 | 1 |
| 30 | 2 | 4 |
| 32 | 4 | 16 |
| (sum) = 168 | 46 |
(mu = frac{24+25+28+29+30+32}{6} = frac{168}{8} = 28)
(S.D = sqrt{frac{sum{(x – mu)^{2}}}{n}} = sqrt{frac{46}{6}})
= (sqrt{7.67} approxeq 2.8)