Co - variance ( x, y ) between a x and y if Σx = 15, Σ y = 40, Σ xy = 110, n = 5 is _______.
22
-2
2
-22
The temperature during a month in summer are recorded as ( in F ) 99, 78, 80, 94, 92, 76, 86, 96 . The mediantemperature is
76
99
92
89
The relationship between mean, median and mode for a moderately skewed distribution is
Mode = 3Median - 2 Mean
Mode = 2 Median - Mean
Mode = 3 Median - 2 Mean
Mode = 2 Median - 3 Mean
G.M of 4, 5, 20, 25 is ______.
8
9
10
11
The central value of the set of observations is called
Mean
Median
Mode
G.M
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 =
7
5
G.M of 4, 5, 20, 25 is
The range of following set of observations : 2, 3, 5, 9, 8, 7, 6, 5, 7, 4, 3, is
5.5
6
The mean of the squares of first n natural numbers is
n2/2
1/8 n ( n + 1 )
1/6 n ( 2n +1 )
1/6 ( n + 1 ) ( 2n + 1 )
One of the methods of determining mode is ______.
mode = 2 median - 3 mean
mode = 2 median + 3 mean
mode = 3 median - 2 mean
mode = 3 median + 2 mean
