Find the mean age from the following data Age ( Years ) : 20 - 30 30 - 40 40 - 50 50 - 60 60 - 70Number of person : 3 5 22 30 2 is
50. 70
49 . 70
48 . 70
47. 70
Geometric means of 2, 2^{2}, 2^{3}, . . . . . 2^{n} is
2^{2/n}
2^{n/2}
2^{n}
2^{(n+1)/2}
The variance of first n natural numbers is
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
If 10 is the mean of a set of 7 observation and 5 is the mean of a st of 3 observations, then the mean of the combined set is
15
10
8.5
7.5
The median of marks of 9 student in a class are 34, 32, 48, 38, 24, 30, 27, 21, 35 is
32
34
38
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
20
27
41
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
If in a frequency distribution, the mean and median are 21 and 22 respectively, then its mode is approximately?
20.5
22.0
24.0
25. 5
The mean of first n - natural number is
^{n}/_{2}