Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter

    Okay the other threads getting way too big and with the server the way it is its impossible to post in there.

    My friend was asking me about the question where you had to approximate the B(100, 0.1). I used a Poission, but he said he used the normal approximation, both should work as the values of n, p, np and nq, satisfy them, do you think either of us will lose marks for using the approximation we did? It said to use a suitable approximation.


    I used a poisson aproximation X~B(100,0.1) : Y~Po(10)

    I beleive that using the poisson is the right aproximation, as you had to use a Normal later on to aproximate a Po(17.75)

    i use normal but i think both is fine

    how did u work out the median?

    this is wot i did:

    f(x) = 1/3 0<=x<1
    = 8x^(3)/45 1<=x<=2
    = 0 elsewhere

    the median will be in the second bit

    so integrate with limits m and 1 making it equal to a half

    rearrange to make x subject

    and you should get a quartic root

    someone validate me

    My immediate thought was to use the Normal approximation because they asked you how to find the mean and the variance in the question before that. But when i thought about it, it seemed so much easier to use Po(10) approximation.

    for the last question F(x) i mistakingly put -13/45 instead of plus 13/45 the question was out of 7 and up till that point it was ok so how many marks would i expect to get?
Turn on thread page Beta
Updated: June 24, 2004
Do you agree with the proposed ban on plastic straws and cotton buds?
Useful resources

Make your revision easier


Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here


How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.