If the arithmetic mean is 25 and geometric mean is 15, then the value of the Harmonic mean is equal to:
9
The harmonic mean (H) is related to the arithmetic mean (A) and the geometric mean (G) by the following formula:
H = 3 / (1/A + 1/G).
Given that the arithmetic mean is 25 and the geometric mean is 15, we can calculate the harmonic mean:
H = 3 / (1/25 + 1/15) = 9.
Important Questions from Mean and Variance of Random variables
A continuous random variable x has a probability density function \(f\left( x \right) = \left\{ {\begin{array}{*{20}{c}} {6x\left( {1 - x} \right),}&{0 < x \le 1}\\ {0,}&{otherwise} \end{array}} \right.\) Then the variance of x is:
X is a non-negative integer valued random variable with
\( P(X = x) =\left\{ \begin{matrix} \dfrac {x+1}{2^{(x+2)}} & x = 0, 1, 2... \\\ 0 & \rm{otherwise} \end{matrix} \right.\)
Then, mean and variance of X are respectively
A random variable X has the distribution law as given below:
X
1
2
3
P(X = x)
0.3
0.4
0.3
The variance of the distribution is:
