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
In a moderately skewed distribution the value of mean and median are 5 and 6 respectively. Then the value of mode is _______.
8
11
16
21
The mean age of 50 persons was found to be 32 years. Later it was detected that the age 28 was wrongly noted as 35, the age 57 was wrongly noted as 30 and the age 60 was wrongly noted as 32. Then the correct mea age is ________.
28
33
31
32.4
The central value of the set of observations is called
Mean
Median
Mode
G.M
The variance of the variates 112, 116, 120 125, 132 about their A.M is
58.8
60
48.8
61.8
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 )
The range of following set of observations : 2, 3, 5, 9, 8, 7, 6, 5, 7, 4, 3, is
7
5.5
6
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
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
10
