Recent questions in Objective type Questions and Answers

The marks secured by $400$ students in a Mathematics test were normally distributed with mean $65$ . If $120$ students got more marks above $85$ , the number of students securing marks between $45$ nd $65$ is

asked Jun 3, 2013 by poojasapani_1

1 answer

If $f(x)$ is a p.d.f of a normal variate $x$ and $X\sim N(\mu,\sigma^{2})$ then $\int\limits_{-\infty}^{\mu}f(x)dx$ is

asked Jun 3, 2013 by poojasapani_1

1 answer

The random variable $X$ follows normal distribution $f(x)=ce\large\frac{-1/2(x-100)^{2}}{25}$ Then the value of $c$ is

asked Jun 3, 2013 by poojasapani_1

1 answer

If $f(x)$ is a p.d.f of a normal distribution with mean $\mu$ then $\int\limits_{-\infty}^{\infty}f(x)dx$ is

asked Jun 3, 2013 by poojasapani_1

1 answer

In a poisson distribution if $P(X=2)=P(X=3)$ then the value of its parameter $\lambda$ is

asked Jun 3, 2013 by poojasapani_1

1 answer

For a poisson distribution with parameter $\lambda=0.25$ the value of the $2^{nd}$ moment about the origin is

asked Jun 3, 2013 by poojasapani_1

1 answer

The distribution function $F(X)$ of a random variable $X$ is

asked Jun 3, 2013 by poojasapani_1

1 answer

If a random variable $X$ follows poisson distribution such that $E(X^{2})=30$ then the variance of the distribution is

asked May 30, 2013 by poojasapani_1

1 answer

If in a poisson distribution $P(X=0)=k$ then the variance is

asked May 30, 2013 by poojasapani_1

1 answer

If $2$ cards are drawn from a well shuffled pack of $52$ cards, the probability that they are of the same colours without replacement, is

asked May 30, 2013 by poojasapani_1

1 answer

A box contains $6$ red and $4$ white balls.If $3$ balls are drawn at random, the probability of getting $2$ white balls without replacement, is

asked May 28, 2013 by poojasapani_1

1 answer

In $16$ throws of a die getting an even number is considered a success. Then the variance of the successes is

asked May 28, 2013 by poojasapani_1

1 answer

If the mean and standard deviation of a binomial distribution are $12$ and $2$ respectively. Then the value of its parameter $p$ is

asked May 28, 2013 by poojasapani_1

1 answer

The mean of a binomial distribution is $5$ and its standard deviation is $2.$ Then the value of $n$ and $p$ are

asked May 28, 2013 by poojasapani_1

1 answer

In $5$ throws of a die, getting $1$ or $2$ is a success. The mean number of successes is

asked May 28, 2013 by poojasapani_1

1 answer

Var $(4X+3)$ is

asked May 28, 2013 by poojasapani_1

1 answer

$\mu_{2}=20, \mu'_{2}=276$ for a discrete random variable $X$ . Then the mean of the random variable $X$ is

asked May 28, 2013 by poojasapani_1

1 answer

Variance of the random variable $X$ is $4$ .Its mean is $2.$ Then $E(X^{2})$ is

asked May 28, 2013 by poojasapani_1

1 answer

$X$ is a random variable taking the values $3, 4$ and $12$ with probabilities $\large\frac{1}{3},\frac{1}{4}$ and $\large\frac{4}{7}.$ Then $E(X)$ is

asked May 28, 2013 by poojasapani_1

1 answer

Given $E(X+c)=8$ and $E(X-c)=12$ then the value of $c$ is

asked May 28, 2013 by poojasapani_1

1 answer

A random variable $X$ has the following p.d.f $\begin{array} {llllllll} \textbf{X:}& 0& 1& 2& 3& 4& 5&6&7 \\ \textbf{P(X):}& 0& k &2k& 2k& 3k& k^{2}&2k^{2}&7k^{2}+k \end{array}$ The value of $k$ is

asked May 28, 2013 by poojasapani_1

1 answer

$X$ is a discrete random variable which takes the values $0, 1, 2$ and $P(X=0)=\large\frac{144}{169},$ $P(X=1)=\large\frac{1}{169}$ then the value of $P(X=2)$ is

asked May 28, 2013 by poojasapani_1

1 answer

A random variable $X$ has the following probability mass function as follows: $\begin{array} {llllllll} \textbf{X:}& -2& 3 & 1 \\ \textbf{P(X=x):}& \large\frac{\lambda}{6}& \large\frac{\lambda}{4} &\large\frac{\lambda}{12} \end{array}$ Then the value of $\lambda$ is

asked May 28, 2013 by poojasapani_1

1 answer

A random variable $X$ has the following probability distribution. $\begin{array} {llllllll} \textbf{X:}& 0& 1& 2& 3& 4& 5 \\ \textbf{P(X=x):}& 1/4& 2a &3a& 4a& 5a& 1/4 \end{array}$ Then $p(1\leq x\leq 4)$ is

asked May 28, 2013 by poojasapani_1

1 answer

If $f(x)=\large\frac{A}{\pi}\frac{1}{16+x^{2'}}$ $-\infty<x<\infty$ is a p.d.f of a continuous random variable $X,$ then the value of $A$ is

asked May 28, 2013 by poojasapani_1

1 answer

If $f(x) = \left\{ \begin{array}{l l} kx^{2}, & \quad \text{$0<x<3$}\\ 0, & \quad \text{elsewhere} \end{array} \right.$ is a probability density function then the value of $k$ is

asked May 28, 2013 by poojasapani_1

0 answers

In the set of integers under the operation $^\ast$ defined by $a^{\ast}b=a+b-1$ the identity element is

asked May 27, 2013 by poojasapani_1

1 answer

In the multiplicative group of $n{ th }$ roots of unity, the inverse of $\omega^{k}$ is $(k<n)$

asked May 27, 2013 by poojasapani_1

1 answer

The order of $-i$ in the multiplicative group of $4^{th}$ roots of unity is

asked May 27, 2013 by poojasapani_1

1 answer

Which of the following is correct?

asked May 27, 2013 by poojasapani_1

1 answer

In the set of real numbers $R,$ an operation $^\ast$ is defined by $a^\ast b=\sqrt{a^{2}+b^{2}}.$ Then the value of $(3^\ast4)^\ast 5$ is

asked May 27, 2013 by poojasapani_1

1 answer