Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

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