Recent questions tagged sec-1

A continuous random variable $x$ has the p.d.f defined by $f(x) = \left\{ \begin{array}{1 1} ce^{-ax} & \quad 0 < x < \infty \\ 0 & \quad \text{else where} \end{array} \right.$ Find the value of $c$ if $a>0$

asked Apr 19, 2013 by poojasapani_1

1 answer

For the distribution function given by $f(x) = \left\{ \begin{array}{l l} 0&\quad\text{x<0}\\ x^{2} & \quad \text{$0$$\leq$$x$$\leq$$1$}\\ 1 & \quad \text{x>1} \end{array} \right.$\[\] Find the density function. Also evaluate $p(x>0.75)$

asked Apr 19, 2013 by poojasapani_1

1 answer

For the distribution function given by $f(x) = \left\{ \begin{array}{l l} 0&\quad\text{x<0}\\ x^{2} & \quad \text{$0$$\leq$$x$$\leq$$1$}\\ 1 & \quad \text{x>1} \end{array} \right.$\[\] Find the density function. Also evaluate $p(x\leq0.5)$

asked Apr 19, 2013 by poojasapani_1

1 answer

For the distribution function given by $f(x) = \left\{ \begin{array}{l l} 0&\quad\text{x<0}\\ x^{2} & \quad \text{$0$$\leq$$x$$\leq$$1$}\\ 1 & \quad \text{x>1} \end{array} \right.$\[\] Find the density function. Also evaluate p(0.5< x <0.75)

asked Apr 19, 2013 by poojasapani_1

1 answer

The probability density function of a random variable $x$ is $f(x) = \left\{ \begin{array}{l l} kx^{\alpha-1}e^{-\beta\;x^{\alpha}}, & \quad \text{x,$\alpha$$,\beta$>$0$}\\ 0 ,& \quad \text{elsewhere} \end{array} \right.$, Find $p(x$>$10)$

asked Apr 19, 2013 by poojasapani_1

1 answer

The probability density function of a random variable $x$ is $f(x) = \left\{ \begin{array}{l l} kx^{\alpha-1}e^{-\beta\;x^{\alpha}}, & \quad \text{x,$\alpha$$,\beta$>$0$}\\ 0 ,& \quad \text{elsewhere} \end{array} \right.$ \[\] Find $k$

asked Apr 19, 2013 by poojasapani_1

1 answer

For the p.d.f $f(x) = \left\{ \begin{array}{l l} cx(1-x)^{3}, & \quad \text{0 $<$ x$<$1}\\ 0 & \quad \text{elsewhere} \end{array} \right.$ \[\]Find $p(x<\large\frac{1}{2})$

asked Apr 19, 2013 by poojasapani_1

1 answer

For the p.d.f $f(x) = \left\{ \begin{array}{l l} cx(1-x)^{3}, & \quad \text{0 $<$ x$<$1}\\ 0 & \quad \text{elsewhere} \end{array} \right.$ \[\]Find the constant $c$

asked Apr 19, 2013 by poojasapani_1

1 answer

A discrete random variable $x$ has the following probability distribution. Find the value of $a$ \[\] $\begin{array} {llllllll} X:& 0& 1& 2& 3& 4& 5& 6& 7& 8 &\\ {P(X):}& a& 3a &5a& 7a& 9a &11a &13a &15a&17a \end{array}$

asked Apr 18, 2013 by poojasapani_1

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A discrete random variable $x$ has the following probability distributioxs.Find $p(x<3)$\[\]$\begin{array} {llllllll} X:& 0& 1& 2& 3& 4& 5& 6& 7& 8 &\\ {P(X):}& a& 3a &5a& 7a& 9a &11a &13a &15a&17a \end{array}$

asked Apr 18, 2013 by poojasapani_1

1 answer

A discrete random variable $x$ has the following probability distributioxs. Find$ p(3$$<$$x$$<$$7)$\[\]$\begin{array} {llllllll} X:& 0& 1& 2& 3& 4& 5& 6& 7& 8 &\\ {P(X):}& a& 3a &5a& 7a& 9a &11a &13a &15a&17a \end{array}$

asked Apr 18, 2013 by poojasapani_1

1 answer

Verify that the following are probability density functions.$f(x)=\large\frac{1}{\pi}\frac{1}{(1+x^{2})'}$$-\infty$$<$$x$$<\infty $

asked Apr 18, 2013 by poojasapani_1

1 answer

Verify that the following are probability density functions.$f(x) = \left\{ \begin{array}{l l} \frac { 2x}{9} & \quad \text{0 $\leq$ x$\leq$3}\\ 0 & \quad \text{elsewhere} \end{array} \right.$

asked Apr 18, 2013 by poojasapani_1

1 answer

A radioactive substance disintegrates at a rate proportional to its mass. When its mass is $10 $mgm, the rate of disintegration is $0.051$ mgm per day. How long will it take for the mass to be reduced from $10$mgm to $5$mgm.$ [\log_{e}$$2=0.6931]$

asked Apr 17, 2013 by poojasapani_1

1 answer

The rate at which the population of a city increases at any time is propotional to the population at that time. If there were $1,30,000$ people in the city in $1960 $ and $1,60,000$ in $1990$ what population may be anticipated in $2020$.$[\log_{e}(\large\frac{16}{13})=$$.2070;$$e^{.42}=1.52]$

asked Apr 17, 2013 by poojasapani_1

1 answer

A cup of coffee at temperature $100^{\circ}$$C$ is placed in a room whose temperature is $15^ {\circ}$$C$ and it cools to $60^{\circ}$$C$ in $5$ minutes . Find its temperature after a further interval of $5$ minutes.

asked Apr 17, 2013 by poojasapani_1

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The sum of Rs $1000$ is compounded continuously, the nominal rate of interest being four percent per annum. In how many years will the amount be twice the original principal ? $(\log_{e}$$2=0.6931)$

asked Apr 17, 2013 by poojasapani_1

1 answer