Question

a study determined that 17% of a population use a certain brand of laundry detergent. What is the probability that more than 2 shoppers selected at random from 11 shoppers use that brand of detergent?

Answer 1

another binomial

Answer 2

\[P(x=k)=\binom{n}{k}p^k(1-p)^{n-k}\]with
\[n=11,k=2,p=.17,1-p=.83\]

Answer 3

you got this or no? "more than 2" means you have to compute
\[P(x=0) , P(x=1), P(x=2)\]add them up and then subtract the answer from 1

Answer 4

ooo i was just calculating it with K = 2

Answer 5

i got 0.716074 by adding x =0 , x = 1 x=2.. whereas the answer is .2839

Answer 6

you have to subtract from 1

Answer 7

it is "more than 2" so you compute 0, 1, and 2, then subtract the result from 1

Answer 8

which is much easier than computing 3, 4, 5, 6, 7, 8, 9,10, 11 and adding all that up!