Business Statistics 11. S.D(X) = 6 and S.D(Y) = 8. If X and Yare independent random variables, then S.D(X-Y) is:
2 10 14 100 View answer Correct answer: (B) 10
12. The ratio of the standard deviation to the arithmetic mean expressed as a percentage is called:
Coefficient of standard deviation Coefficient of skewness Coefficient of kurtosis Coefficient of variation View answer Correct answer: (D) Coefficient of variation
13. To compare the variation of two or more than two series, we use
Combined standard deviation Corrected standard deviation Coefficient of variation Coefficient of skewness View answer Correct answer: (C) Coefficient of variation
14. If standard deviation of the values 2, 4, 6, 8 is 2.236, then standard deviation of the values 4, 8,12, 16 is:
0 4.472 4.236 2.236 View answer Correct answer: (B) 4.472
15. The moments about mean are called:
Raw moments Central moments Moments about origin All of the above View answer Correct answer: (B) Central moments
16. Moment ratios β1 and β2 are:
Independent of origin and scale of measurement Expressed in original unit of the data Unit less quantities Both (a) and (c) View answer Correct answer: (C) Unit less quantities
17. If the third moment about mean is zero, then the distribution is:
Positively skewed Negatively skewed Symmetrical Mesokurtic View answer Correct answer: (C) Symmetrical
18. If mean=25, median=30 and standard deviation=15, the distribution will be:
Symmetrical Positively skewed Negatively skewed Normal View answer Correct answer: (C) Negatively skewed
19. In a symmetrical distribution, Q3 – Q1 = 20, median = 15. Q3 is equal to:
5 15 20 25 View answer Correct answer: (D) 25
20. The degree of peaked ness or flatness of a unimodel distribution is called:
Skewness Symmetry Dispersion Kurtosis View answer Correct answer: (D) Kurtosis