Question

In a data set what is the variance of 68194

Answer 1

Variance is a measure of scatter or dispersion.

The variance of a set of ’n’ values x1, x2, x3,…,xn with mean ‘x’ measures actually the amount of spread or scatterness of the values x1, x2,…, xn from their mean ‘x’ and is given by the formula ;

1/n (summation (xi-x)^2) ( i =1 (|) n )..(i)

Thus variance of a constant always results in 0 as a constant value has mean as itself and it is ‘0’ units scattered from itself→this is the logic.

Also, putting xi=c ( a constant ) in (i) we get the same result mathematically..

1/n (summation (c-c)^2) = 0

As, 68194 is a constant value its variance is ‘0’.

Answer 2

Question :- What is the variance of the data set :-

86, 49, 63, 90, 82, 98, 36.

Solution :-

we know that,

• Mean = sum of all observations / Total number of observations

so,

→ Mean of given data = xi = (86 + 49 + 63 + 90 + 82 + 98 + 36) / 7 = 504 / 7 = 72 .

then,

x (x - xi) (x - xi)²

86 (-12) 144

49 (-23) 529

63 (-9) 81

90 18 324

82 10 100

98 26 676

36 36 1296

⅀(x - xi)² = 3150

therefore ,

→ variance of the set of data = ⅀(x - xi)² / (n - 1)

→ variance of the set of data = 3150 / (7 - 1)

→ variance of the set of data = 3150 / 6

→ variance of the set of data = 525 (Ans.)

Learn more :-

calculate the median and mode from the following income between (rs)100-200 100-300 100-400 100-500 100-600 no of person...

https://brainly.in/question/23585381

Some students of class X donated for the welfare of old age persons. The contributions are shown in the following distri...

https://brainly.in/question/17314012