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
and n = 10, then the coefficient of correlation is:
0.1
0.3
0.2
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)
The mode of the series 3, 4, 2, 6, 1, 7,6 7, 6, 8, 9, 5 is:
5
6
7
8
The values of mean, median and mode coincide, then the distribution is:
Positive skewness
Symmetric distribution
Negative skewness
All of the above
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
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
The mean deviation from the mean of the set of observations -1, 0, 4 is
3
1
-2
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 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
