The mean of 5 numbers is 18. If one number is excluded, their mean becomes 16, then the excluded number is
18
25
26
30
The mean deviation from the observations 3, 8, 12, 19, 20 is
6.5
7.9
8.5
9.7
The mean age of the combined group of men and women is 25 years. If the mean age of the group of men is 26 and
that of the women is 21, then the percentage of men and women in the group is
60, 40
80, 20
20, 80
40, 60
One of the method of determining mode is
Mode = 2 median - 3 mean
Mode = 2 median + 3 mean
Mode = 3 median - 2 mean
Mode = 3 median + 2 mean
The mean of 9 observation is 100 and that of 6 observations is 80, then the combined mean of all 15 observation is
100
92
90
80
If in a moderately skewed distribution the value of mode and mean are 6 λ and 9λ respectively, then the value of the median is ______.
8 λ
7 λ
6 λ
5 λ
The means of the series 1, 2, 4, 8, - - - - 2^{n} is
The marks obtained in chemistry by the 15 students of class XI B are
20, 15, 10, 20 27, 28, 27, 10, 20, 30 35, 40, 41, 41, 20 then the value of mode is
10
20
27
41
The variance of first n natural numbers is
The mean of first n - natural number is
^{n}/_{2}