$min{X, Y}$ is geometrically distributed according to parameter $1 - (1-p)^{2}$
Let $X,Y$ be independent from the parameter $0 < p < 1$ distributed random variable on a discrete probability space $(Omega, mathcal{F}, mathbb P)$. Show that $min{X,Y}$ is geometrically distrbuted to $1-(1-p)^{2}$.
Steps:
I am having trouble understanding what it is my end result has to be, in order to show that it is indeed geometrically distributed. I mean for a geometric distribution $mathbb P(k) = p(1-p)^{k-1}$ for parameter $p$, but how exactly am I showing a geometric distribution?
$mathbb P( min{X,Y} > k)=mathbb P((X>k) cap (Y>k))$ and then what?
In terms of the parameter, I've got: $(1-(1-p)^{2})(1-(1-(1-p)^{2}))=p^{2}(2-p)^{2}$
I do not understand how the two work together...
real-analysis probability-theory stochastic-processes geometric-probability
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Let $X,Y$ be independent from the parameter $0 < p < 1$ distributed random variable on a discrete probability space $(Omega, mathcal{F}, mathbb P)$. Show that $min{X,Y}$ is geometrically distrbuted to $1-(1-p)^{2}$.
Steps:
I am having trouble understanding what it is my end result has to be, in order to show that it is indeed geometrically distributed. I mean for a geometric distribution $mathbb P(k) = p(1-p)^{k-1}$ for parameter $p$, but how exactly am I showing a geometric distribution?
$mathbb P( min{X,Y} > k)=mathbb P((X>k) cap (Y>k))$ and then what?
In terms of the parameter, I've got: $(1-(1-p)^{2})(1-(1-(1-p)^{2}))=p^{2}(2-p)^{2}$
I do not understand how the two work together...
real-analysis probability-theory stochastic-processes geometric-probability
add a comment |
Let $X,Y$ be independent from the parameter $0 < p < 1$ distributed random variable on a discrete probability space $(Omega, mathcal{F}, mathbb P)$. Show that $min{X,Y}$ is geometrically distrbuted to $1-(1-p)^{2}$.
Steps:
I am having trouble understanding what it is my end result has to be, in order to show that it is indeed geometrically distributed. I mean for a geometric distribution $mathbb P(k) = p(1-p)^{k-1}$ for parameter $p$, but how exactly am I showing a geometric distribution?
$mathbb P( min{X,Y} > k)=mathbb P((X>k) cap (Y>k))$ and then what?
In terms of the parameter, I've got: $(1-(1-p)^{2})(1-(1-(1-p)^{2}))=p^{2}(2-p)^{2}$
I do not understand how the two work together...
real-analysis probability-theory stochastic-processes geometric-probability
Let $X,Y$ be independent from the parameter $0 < p < 1$ distributed random variable on a discrete probability space $(Omega, mathcal{F}, mathbb P)$. Show that $min{X,Y}$ is geometrically distrbuted to $1-(1-p)^{2}$.
Steps:
I am having trouble understanding what it is my end result has to be, in order to show that it is indeed geometrically distributed. I mean for a geometric distribution $mathbb P(k) = p(1-p)^{k-1}$ for parameter $p$, but how exactly am I showing a geometric distribution?
$mathbb P( min{X,Y} > k)=mathbb P((X>k) cap (Y>k))$ and then what?
In terms of the parameter, I've got: $(1-(1-p)^{2})(1-(1-(1-p)^{2}))=p^{2}(2-p)^{2}$
I do not understand how the two work together...
real-analysis probability-theory stochastic-processes geometric-probability
real-analysis probability-theory stochastic-processes geometric-probability
asked Nov 18 at 14:09
SABOY
549311
549311
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begin{align}
P(min(X,Y) > k) &= P(X > k, Y>k) \
&= P(X > k)P(Y>k) \
&= P(X >k)^2 \
&=((1-p)^2)^{k}
end{align}
Hence the CDF is $1-((1-p)^2)^k=1-(1-color{blue}{(1-(1-p)^2)})^k$
Hence it is a geometric distribution (we just have to compare with the CDF of a geometric distribution) with success probability $1-(1-p)^2.$
Thank you! Please just remind me why we can assume $P(X > k)P(Y > k)= P(X > k)^{2}$. And then adding on to that why would it be equal to $((1-p)^{2})^{k}$?
– SABOY
Nov 18 at 14:26
$X$ and $Y$ are IID. Also we have $P(X > k)=(1-p)^k$.
– Siong Thye Goh
Nov 18 at 14:29
In the pre-text, it was only stated that the $X, Y$ are independent. Can I automatically assume IID?
– SABOY
Nov 18 at 14:31
1
they are both geometric distribution with probability $p$ isn't it?
– Siong Thye Goh
Nov 18 at 14:33
But the OP didn't actually state that.
– Robert Israel
Nov 18 at 14:35
add a comment |
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1 Answer
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begin{align}
P(min(X,Y) > k) &= P(X > k, Y>k) \
&= P(X > k)P(Y>k) \
&= P(X >k)^2 \
&=((1-p)^2)^{k}
end{align}
Hence the CDF is $1-((1-p)^2)^k=1-(1-color{blue}{(1-(1-p)^2)})^k$
Hence it is a geometric distribution (we just have to compare with the CDF of a geometric distribution) with success probability $1-(1-p)^2.$
Thank you! Please just remind me why we can assume $P(X > k)P(Y > k)= P(X > k)^{2}$. And then adding on to that why would it be equal to $((1-p)^{2})^{k}$?
– SABOY
Nov 18 at 14:26
$X$ and $Y$ are IID. Also we have $P(X > k)=(1-p)^k$.
– Siong Thye Goh
Nov 18 at 14:29
In the pre-text, it was only stated that the $X, Y$ are independent. Can I automatically assume IID?
– SABOY
Nov 18 at 14:31
1
they are both geometric distribution with probability $p$ isn't it?
– Siong Thye Goh
Nov 18 at 14:33
But the OP didn't actually state that.
– Robert Israel
Nov 18 at 14:35
add a comment |
begin{align}
P(min(X,Y) > k) &= P(X > k, Y>k) \
&= P(X > k)P(Y>k) \
&= P(X >k)^2 \
&=((1-p)^2)^{k}
end{align}
Hence the CDF is $1-((1-p)^2)^k=1-(1-color{blue}{(1-(1-p)^2)})^k$
Hence it is a geometric distribution (we just have to compare with the CDF of a geometric distribution) with success probability $1-(1-p)^2.$
Thank you! Please just remind me why we can assume $P(X > k)P(Y > k)= P(X > k)^{2}$. And then adding on to that why would it be equal to $((1-p)^{2})^{k}$?
– SABOY
Nov 18 at 14:26
$X$ and $Y$ are IID. Also we have $P(X > k)=(1-p)^k$.
– Siong Thye Goh
Nov 18 at 14:29
In the pre-text, it was only stated that the $X, Y$ are independent. Can I automatically assume IID?
– SABOY
Nov 18 at 14:31
1
they are both geometric distribution with probability $p$ isn't it?
– Siong Thye Goh
Nov 18 at 14:33
But the OP didn't actually state that.
– Robert Israel
Nov 18 at 14:35
add a comment |
begin{align}
P(min(X,Y) > k) &= P(X > k, Y>k) \
&= P(X > k)P(Y>k) \
&= P(X >k)^2 \
&=((1-p)^2)^{k}
end{align}
Hence the CDF is $1-((1-p)^2)^k=1-(1-color{blue}{(1-(1-p)^2)})^k$
Hence it is a geometric distribution (we just have to compare with the CDF of a geometric distribution) with success probability $1-(1-p)^2.$
begin{align}
P(min(X,Y) > k) &= P(X > k, Y>k) \
&= P(X > k)P(Y>k) \
&= P(X >k)^2 \
&=((1-p)^2)^{k}
end{align}
Hence the CDF is $1-((1-p)^2)^k=1-(1-color{blue}{(1-(1-p)^2)})^k$
Hence it is a geometric distribution (we just have to compare with the CDF of a geometric distribution) with success probability $1-(1-p)^2.$
answered Nov 18 at 14:17
Siong Thye Goh
99.1k1464117
99.1k1464117
Thank you! Please just remind me why we can assume $P(X > k)P(Y > k)= P(X > k)^{2}$. And then adding on to that why would it be equal to $((1-p)^{2})^{k}$?
– SABOY
Nov 18 at 14:26
$X$ and $Y$ are IID. Also we have $P(X > k)=(1-p)^k$.
– Siong Thye Goh
Nov 18 at 14:29
In the pre-text, it was only stated that the $X, Y$ are independent. Can I automatically assume IID?
– SABOY
Nov 18 at 14:31
1
they are both geometric distribution with probability $p$ isn't it?
– Siong Thye Goh
Nov 18 at 14:33
But the OP didn't actually state that.
– Robert Israel
Nov 18 at 14:35
add a comment |
Thank you! Please just remind me why we can assume $P(X > k)P(Y > k)= P(X > k)^{2}$. And then adding on to that why would it be equal to $((1-p)^{2})^{k}$?
– SABOY
Nov 18 at 14:26
$X$ and $Y$ are IID. Also we have $P(X > k)=(1-p)^k$.
– Siong Thye Goh
Nov 18 at 14:29
In the pre-text, it was only stated that the $X, Y$ are independent. Can I automatically assume IID?
– SABOY
Nov 18 at 14:31
1
they are both geometric distribution with probability $p$ isn't it?
– Siong Thye Goh
Nov 18 at 14:33
But the OP didn't actually state that.
– Robert Israel
Nov 18 at 14:35
Thank you! Please just remind me why we can assume $P(X > k)P(Y > k)= P(X > k)^{2}$. And then adding on to that why would it be equal to $((1-p)^{2})^{k}$?
– SABOY
Nov 18 at 14:26
Thank you! Please just remind me why we can assume $P(X > k)P(Y > k)= P(X > k)^{2}$. And then adding on to that why would it be equal to $((1-p)^{2})^{k}$?
– SABOY
Nov 18 at 14:26
$X$ and $Y$ are IID. Also we have $P(X > k)=(1-p)^k$.
– Siong Thye Goh
Nov 18 at 14:29
$X$ and $Y$ are IID. Also we have $P(X > k)=(1-p)^k$.
– Siong Thye Goh
Nov 18 at 14:29
In the pre-text, it was only stated that the $X, Y$ are independent. Can I automatically assume IID?
– SABOY
Nov 18 at 14:31
In the pre-text, it was only stated that the $X, Y$ are independent. Can I automatically assume IID?
– SABOY
Nov 18 at 14:31
1
1
they are both geometric distribution with probability $p$ isn't it?
– Siong Thye Goh
Nov 18 at 14:33
they are both geometric distribution with probability $p$ isn't it?
– Siong Thye Goh
Nov 18 at 14:33
But the OP didn't actually state that.
– Robert Israel
Nov 18 at 14:35
But the OP didn't actually state that.
– Robert Israel
Nov 18 at 14:35
add a comment |
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