The mean of the squares of first n natural numbers is
1/8 n ( n + 1 )
1/6 n ( 2n +1 )
1/6 ( n + 1 ) ( 2n + 1 )
For the following data, mean of x is found to be 7.3. The missing frequency is x: 5 6 7 8 9 f : 4 6 12 - 8
10
9
8
7
In a moderately skewed distrbution, the values of mean and median are 5 and 6 respectively. The value of mode in such a situation is nearly equal to
11
16
None of these
The harmonic mean of the numbers 2, 3, 4 is _______.
3
( 24 )1/3
36/13
13/36
The AM of three sizes 3, 4 and 2.5 weighted respectively by the numbers 15, 5 and x is found to be 3. Then x =
5
If the regression coefficients are o.8 and 0.2, then the value of co - efficients of correlation is
0.16
0.4
0.04
The relationship between mean, median and mode for a moderately skewed distribution is
Mode = Median - 2 Mean
Mode = 2 Median - Mean
Mode = 3 Median - 2 Mean
Mode = 2 Median - 3 Mean
For a given distribution of marks mean is 35. 16 and its standard deviation is 19. 76. The coefficient of variation is _____.
The central value of the set of observations is called
Mean
Median
Mode
G.M
