Assignment X3 number 7

Discussion in 'SP8' started by mbuta, Apr 6, 2023.

  1. mbuta

    mbuta Made first post

    Hi,

    could someone explain to me how a negative binomial gives

    P(N=n) = (n+2 c n)(0.9)^3(0.1)^n.

    I managed to get that k = 3 and p = 0.9 but by reference to the tables negative type II binomial I just can't figure it out...

    Thanks,
    MB
     
    mbuta, Apr 6, 2023
    #1
  2. Busy_Bee4422

    Busy_Bee4422 Ton up Member

    Hi

    If you have your third success at the (n +3)th time then you just need to see how many ways n failures can happen in n +2 tries.

    PS This is an SP8 question.

    Edit by Admin: moved to SP8 forum
     
    Last edited by a moderator: Apr 8, 2023
    Busy_Bee4422, Apr 7, 2023
    #2

Share This Page