[nmudz_009]

7bii) may2009 st : "calculate the probrability, when sorting a batch of 35 letters, mrs fewer sorts atleast one letter incorrectly. This is a binomial distribution question, but I have no idea how to go about it, since n=35 table isn't in the formula booklet, and I've tried using the formula, (using x=0 and x=1) but the answer made no sense. I couldn't understand the markscheme either. Thanks for any replies!! (P=0.06) for this. Each sorting of a letter may be assumed to be in dependant.

[CallumTM]

Just work out the probabality she sorts none incorrectly and subtract the answer from 1, atleast this is what i'd do, not sure if it's correct :/

[nmudz_009]

(Original post by CallumTM)
Just work out the probabality she sorts none incorrectly and subtract the answer from 1, atleast this is what i'd do, not sure if it's correct :/

Thats what I did, I substituted x=0 and got 1 as the answer but that cant be right?

[the bear]

The distribution of wrongly sorted letters is
Bin(35,0.06)

The chance of zero mistakes is
³⁵C₀*(0.06)⁰*(0.94)³⁵

Then subtract from 1