# Math Help - Probability Distribution Help?

1. ## Probability Distribution Help?

Hey there,

I was wondering if anyone could shed any light on thse questions. My knowledge in this area is sketchy. I would welcome any help greatly!

Kind Regards,
Ross

2. Originally Posted by RossBrons
Hey there,

I was wondering if anyone could shed any light on thse questions. My knowledge in this area is sketchy. I would welcome any help greatly!

Kind Regards,
Ross
I have time for Q19 (i) and (ii):

Mean: $E(X) = \int_{-\infty}^{\infty} x \, f(x) \, dx = \int_0^1 x \, 2 (1 - x) \, dx = \int_0^1 2x (1 - x) \, dx = \, ....$

Variance: $Var(X) = E(X^2) - [E(X)]^2$.

$E(X^2) = \int_{-\infty}^{\infty} x^2 \, f(x) \, dx = \int_0^1 x^2 \, 2 (1 - x) \, dx = \int_0^1 2x^2 (1 - x) \, dx = \, ....$

(iii) You should do some research.

3. Originally Posted by RossBrons
Hey there,

I was wondering if anyone could shed any light on thse questions. My knowledge in this area is sketchy. I would welcome any help greatly!
Kind Regards,
Ross

4. Originally Posted by mr fantastic
I have time for Q19 (i) and (ii):

Mean: $E(X) = \int_{-\infty}^{\infty} x \, f(x) \, dx = \int_0^1 x \, 2 (1 - x) \, dx = \int_0^1 2x (1 - x) \, dx = \, ....$

Variance: $Var(X) = E(X^2) - [E(X)]^2$.

$E(X^2) = \int_{-\infty}^{\infty} x^2 \, f(x) \, dx = \int_0^1 x^2 \, 2 (1 - x) \, dx = \int_0^1 2x^2 (1 - x) \, dx = \, ....$

(iii) You should do some research.
Regarding (iii):

1. Read this (well I think it's funny and it's something I didn't know): Urban Dictionary: grauniad

2. Read this regarding iii (c): Poisson distribution

3. Read this regarding iii (a): Poisson process - Wikipedia, the free encyclopedia

Now read this: Poisson distribution - Wikipedia, the free encyclopedia

So which option does that leave ....?