Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

Login

Username

Password

Not registered yet?

#1 2006-04-29 19:10:06

Ross
Guest

a bit of stats and integration question

Hope that someone can help.

the probability density function is given by f(x)= 1/48 (x+4),   -4 < x < 4
to get the CDF, we have to integrate it in the following way.
F(x) = ∫ 1/48 (t+4) dt, the upper limit is x and the lower limit is -4
can anybody help me integrate it. also the second part of the question says, using the CDF, get the median and the inter-quartile of X. I don't know how to get that either.

Plzzz i need to do this urgently.

Thanks.

#2 2006-05-01 23:43:05

George,Y
Super Member

Offline

Re: a bit of stats and integration question

You've got a wrong problem
Total probability (integral of PDF from -4 to 4) is infinite because ln0=-∞ .
That contradicts the rule that total probability is 1.


X'(y-Xβ)=0

#3 2006-05-02 21:25:00

Ross
Guest

Re: a bit of stats and integration question

yeah i have made a mistake here.
my integral should be f(x)= 1/32 (x+4)

I wish that you can help me doing the problem now...

#4 2006-05-04 00:47:11

George,Y
Super Member

Offline

Re: a bit of stats and integration question





CDF(median)=1/2
CDF(lower quatile)=1/4
CDF(upper quatile)=3/4
-you can solve the three using the expression of CDF yourself now:D

Last edited by George,Y (2006-05-04 00:49:17)


X'(y-Xβ)=0

Board footer

Powered by FluxBB