Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    2
    ReputationRep:
    what kind of approximation would you use for these:

    1. A fair die is rolled and the number of sixes obtained is recorded. Using suitablle approximations find the probablility of:
    a. No more than 10 sixes in 48 rolls of the die.


    For a. the n is quite small, even though the p is small too so I always get confused whether to use binomial-poisson or not and since this question is in the normal approximations section of the book I dont know what to use because p isnt close to 0.5 either.
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by fpmaniac)
    what kind of approximation would you use for these:

    1. A fair die is rolled and the number of sixes obtained is recorded. Using suitablle approximations find the probablility of:
    a. No more than 10 sixes in 48 rolls of the die.


    For a. the n is quite small, even though the p is small too so I always get confused whether to use binomial-poisson or not and since this question is in the normal approximations section of the book I dont know what to use because p isnt close to 0.5 either.
    Personally I ignore those arbitrary conditions (although it is important to remember then and be able to recite them), and test out the poisson approximation like so: the tables (for Edexcel, at least) only go up to 10, so if the proposed lamba (i.e lambda = np) was greater than 10, then a normal approximation is suitable. If not, go for possion. (Basically, if you can use thet ables with poisson, go for it, if you can't then use normal).
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by SeanFM)
    Personally I ignore those arbitrary conditions (although it is important to remember then and be able to recite them), and test out the poisson approximation like so: the tables (for Edexcel, at least) only go up to 10, so if the proposed lamba (i.e lambda = np) was greater than 10, then a normal approximation is suitable. If not, go for possion. (Basically, if you can use thet ables with poisson, go for it, if you can't then use normal).
    Thanks!
 
 
 
Poll
Do you agree with the PM's proposal to cut tuition fees for some courses?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

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