Advertisement
Help Keep Boards Alive. Support us by going ad free today. See here: https://subscriptions.boards.ie/.
If we do not hit our goal we will be forced to close the site.

Current status: https://keepboardsalive.com/

Annual subs are best for most impact. If you are still undecided on going Ad Free - you can also donate using the Paypal Donate option. All contribution helps. Thank you.
https://www.boards.ie/group/1878-subscribers-forum

Private Group for paid up members of Boards.ie. Join the club.

Problem calculating binomial distribution.

  • 09-01-2010 09:30PM
    #1
    DeadMoney
    Registered Users, Registered Users 2 Posts: 1,127 ✭✭✭


    Hi, I am going through some tutorials for frequency distributions and am getting stuck on binomial distribution. I know how it works but just can't work through the formula properly.

    For example, in a sample question p= .3 and 1-p = .7 and n=5

    I can't really type out the formula here as it will look messy but following the binomial formula the answer for P(O) = .168 (according to the tutorial note)

    The bit I am getting stuck as is just working through the formula. Can anybody work out the P(O) here using these figures?
    Thanks


Comments

  • #2
    gerry87
    Registered Users, Registered Users 2 Posts: 872 ✭✭✭gerry87


    DeadMoney wrote: »
    Hi, I am going through some tutorials for frequency distributions and am getting stuck on binomial distribution. I know how it works but just can't work through the formula properly.

    For example, in a sample question p= .3 and 1-p = .7 and n=5

    I can't really type out the formula here as it will look messy but following the binomial formula the answer for P(O) = .168 (according to the tutorial note)

    The bit I am getting stuck as is just working through the formula. Can anybody work out the P(O) here using these figures?
    Thanks

    P(O) is probably P(0), which would fit in to the formula, its usually as "r" or "k", anyway:

    P(k) = (n choose k) * [(p)^(k)] * [(1-p)^(n-k)]

    so,

    P(0) = (5 choose 0) * [(.3)^0 ] * [(.7)^5]
    = 1*1*(.7^5)
    = 0.16807


Advertisement