i. The standard deviation is the positive square root of the variance. ii. For a symmetrical distribution, the variance is equal to the standard deviation.
iii. If the standard deviation of the ages of a female group of employees is six years and the standard deviation of the ages of a male group in the same plant is ten years, it indicates that there is more spread in the ages of the female employees.
A) (i), (ii) and (iii) are all correct statements
B) (i) and, (ii) are correct statements but not (iii).
C) (i) and, (iii) are correct statements but not (ii).
D) (i) is a correct statement, but not (ii) or (iii).
E) (i), (ii) and (iii) are all false statements

Question

Quizplus · Accepted Answer

(i) is correct because the standard deviation is indeed the positive square root of the variance. (ii) is incorrect because the variance is the square of the standard deviation, not equal to it. (iii) is incorrect because a higher standard deviation (ten years for males) indicates more spread in the ages of the male employees, not the female employees.

I the Standard Deviation Is the Positive Square Root of the Variance