1/5
-1/5
-2/5
2/5
If var (x) = 8.25, var (y) = 33. 96 and cov (x,y) = 10.2then the correlation coefficient is:
0.89
-0.98
0.61
-0.16
If in a frequency distribution, the mean and median are 21 and 22 respectively, then its mode is approximately.
24
25.5
20.5
22.0
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
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 standard deviation of the observations -5, -4, 03, -2, -1, 0, 1, 2, 3, 4, 5 is √10. The standard deviation of observations 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 will be.
√10 + 20
√10 + 10
√10
None of these
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
If the variance of 1,2,3,4, ... 10 is 99/12, then the standard deviation of 3, 6, 9, 12, .... 30 is:
The values of mean, median and mode coincide, then the distribution is:
Positive skewness
Symmetric distribution
Negative skewness
All of the above
If the coefficient of variation is 45% and the mean is 12, then its standard deviation is:
5.2
5.3
5.4
5.5
