If r is Karl Pearson's coefficient of correlation between two sets of variates, then:
r < 1
r > 1
r < -1
| r | ≤ 1
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
Consider the following statements i. Mode can be computed from histogram ii. Median is not independent of change of scale iii. Variance is independent of change of origin and scale Which of these is/ are correct?
Only (1)
Only (ii)
Only (i) and (ii)
Only (i), (ii) and (iii)
If the standard deviation of a variable x is σ, then the standard deviation of another variable is:
σ
None of these
The mean and variance of n observations x1, x2, ....x xn are 5 and 0 respectively. If xi2 = 400, then the value of n is equal to.
80
25
20
16
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
In a class of 100 students there are 70 boys whose average marks in a subject are 75. If the average marks of the complete class is 72, then what is the average marks of the girls?
73
65
68
74
and n = 10, then the coefficient of correlation is:
0.1
0.3
0.2
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
10.1
20.2
The mean deviation from the mean of the set of observations -1, 0, 4 is
3
1
-2
2
