The S.D of 15 items is 6 and if each item is decreased or increased by 1, then standard deviation is ____.
5
7
91/15
6
The variance of (, ( and ( is 9, then variance of 5(, 5( and 5( is ____.
45
9/5
5/9
225
A batsman scores runs in 10 innings 38, 70, 48, 34, 42, 55, 63, 46, 54, 44, then the mean deviation is ____.
8.6
6.4
10.6
9.6
The reciprocal of the mean of the reciprocals of n observations is their ____.
A.M.
G.M.
H.M.
None of the above
The A.M. of n observations is M. If the sum of observations is a, then the mean of remaining 4 observations is ____.
n M + a
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 are 72, then what are the average marks of the girls?
73
65
68
74
A school has four sections of chemistry in class XII having 40, 35, 45 and 42 students. The mean marks obtained in chemistry test are 50, 60, 55 and 45 respectively for the four sections, the over all average of marks per students is ____.
53
45
55.3
52. 25
The class marks of a distribution are 6,10, 14, 18, 22, 26, 30 then the class size is ____.
4
2
5
8
Let be n observations such that and . Then a possible value of n among the following is ____.
9
12
15
18
A, B, C are three sets of values of x:
A: 2,3,7,1,3,2,3 B
B: 7,5,9,12,5,3,8
C: 4,4,11,7,2,3,4
Select the correct statement from among the following:
Mean of A is equal to Mode of C
Mean of C is equal to Median of B
Median of B is equal to Mode of A
Mean, Median and Mode of A are same