If the variance of 1,2,3,4, ... 10 is 99/12, then the standard deviation of 3, 6, 9, 12, .... 30 is
The median of a set of 9 distinct observations is 20.5. If each of the largest 4 observations of the set is increased by 2, then the median of the new set.
is increased by 2
is decreased by 2
is two times the original median
remains the same as that of original set.
If the coefficient of variation is 45% and the mean is 12, then its standard deviation is.
5.2
5.3
5.4
None of these
The values of mean, median and mode coincide, then the distribution is.
Positive skewness
Symmetric distribution
Negative skewness
All of the above
For the given data, the calculation corresponding to all values of variates (x,y) is following.The karl Pearson's correlation coefficient is.
0. 2
0.5
0. 66
0. 33
and n = 10, then the coefficient of correlation is
0.1
0.3
0.2
If r is Karl Pearson's coefficient of correlation between two sets of variates, then.
r < 1
r > 1
r < -1
| r | ≤ 1
The Standard deviation of n observations x1,x2,---xn is 2. If xi2 = 100, then n is
10 or 20
5 or 10
5 or 20
5 or 15
1/5
-1/5
2/5
-2/5
If the mean deviation of number 1, 1 + d, 1 + 2d,.... 1 + 100 d from their mean is 255, then d is equal to.
10
20
10. 1
20. 2
