Consider the following statements regarding random variables : 1. A discrete random variable will have a countable number of distinct values. 2. Continuous random variable is defined for the system which generates a finite number of outcomes within a finite period of time. Which of the above statements is/are correct?
We need to evaluate the correctness of two statements regarding random variables.
Based on the analysis, only statement 1 is correct. Therefore, the correct option is the one that includes "1 only".
Consider the following probability density function for a random variable x.
(a) \(f_{1}(x)=1\ ;\ -1\le x\le 1\)
(b) \(f_{2}(x)=x\ ;\ 0\le x\le 1\)
(c) \(f_{3}(x)=(1-x)\ ;\ -1\le x\le 1\)
Arrange the above functions in terms of the increasing value of mean of random variable x.
Considering all the symbols with their usual meanings, match the following :
| List - I | List - II |
| (a) \(f_{X}(x)\) | (i) \(\displaystyle\int_{-\infty}^{\infty}f_{X,Y}(x,y)\,dx\) |
| (b) \(\displaystyle\int_{-\infty}^{\infty}f_{X}(x)\,dx\) | (ii) \(\displaystyle\int_{-\infty}^{a}f_{X}(x)\,dx\) |
| (c) \(F_{X}(a)\) | (iii) \(\displaystyle\int_{-\infty}^{\infty}f_{X,Y}(x,y)\,dy\) |
| (d) \(f_{Y}(y)\) | (iv) 1 |
Codes :
The density function of a random variable is given by \(p(x)=Ke^{-\frac{x^{2}}{2}}\) for \(-\infty \lt x \lt \infty\). The value of K should be :
Consider a discrete random variable X whose probabilities are given below. The standard deviation of the random variable is ________ (round off to one decimal place).
| $x_1$ | 1 | 2 | 3 | 4 |
| $P(X = x_i)$ | 0.3 | 0.1 | 0.3 | 0.3 |