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# Trouble with a Continuous random variable question watch

1. Question: The Continuous Random Variable X has the following probability density function...

f(x)= {a+bx 0 ≤ x ≤ 5
{0 otherwise

Where a and b are constants
(a) Show that 10a + 25b = 2

This was easy and I got it

(b) find a second equation in a and b

This is the one I'm struggling with which doesn't allow me to carry on and do the next two questions which are :

(c) hence find the value of a and the value of b
(d) Find, to 3s.f. the median of X
2. Bump
3. (Original post by TehJokur)
Question: The Continuous Random Variable X has the following probability density function...

f(x)= {a+bx 0 ≤ x ≤ 5
{0 otherwise

Where a and b are constants
(a) Show that 10a + 25b = 2

This was easy and I got it

(b) find a second equation in a and b

This is the one I'm struggling with which doesn't allow me to carry on and do the next two questions which are :

(c) hence find the value of a and the value of b
(d) Find, to 3s.f. the median of X
i think there must be one more piece of information which we need to solve the question... is there anything else ?
4. (Original post by TehJokur)
Question: The Continuous Random Variable X has the following probability density function...

f(x)= {a+bx 0 ≤ x ≤ 5
{0 otherwise

Where a and b are constants
(a) Show that 10a + 25b = 2

This was easy and I got it

(b) find a second equation in a and b

This is the one I'm struggling with which doesn't allow me to carry on and do the next two questions which are :

(c) hence find the value of a and the value of b
(d) Find, to 3s.f. the median of X
This is Edexcel Jan 13 S2 Q7.

You missed the part about E(X). Did you forget to post it or was the question given to you without this information?
5. (Original post by Notnek)
This is Edexcel Jan 13 S2 Q7.

You missed the part about E(X). Did you forget to post it or was the question given to you without this information?
Should've known there was something missing, there I was bashing my head trying to figure out what the hell it is!

(Original post by TehJokur)
Question: The Continuous Random Variable X has the following probability density function...

f(x)= {a+bx 0 ≤ x ≤ 5
{0 otherwise

Where a and b are constants
(a) Show that 10a + 25b = 2

This was easy and I got it

(b) find a second equation in a and b

This is the one I'm struggling with which doesn't allow me to carry on and do the next two questions which are :

(c) hence find the value of a and the value of b
(d) Find, to 3s.f. the median of X
The second equation is given by
6. (Original post by Notnek)
This is Edexcel Jan 13 S2 Q7.

You missed the part about E(X). Did you forget to post it or was the question given to you without this information?
Missed it, E(X)= 35/12

I got the answer a few minutes after posting the question so forgot to check back
7. Anyone able to do part (D)?

EDIT: I got 3.09, anyone get anything different?
8. (Original post by TehJokur)
Anyone able to do part (D)?

EDIT: I got 3.09, anyone get anything different?
That’s right
9. (Original post by RDKGames)
That’s right
yayyy

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