Question

Suppose that you are in a class of 29 students and it is assumed that approximately 16% of the population is left-handed. (Give your answers correct to three decimal places.)
(a) Compute the probability that exactly five students are left-handed.

(b) Compute the probability that at most four students are left-handed.


(c) Compute the probability that at least six students are left-handed.

Answer 1

Formula:

P(x) = (nCx)(p^x)[q^(n-x)]

For (a):

x = 5
p = .16
q = 1 - p = 1 - .16 = .84
n = 29

Substitute and calculate for your probability.

For (b):

x = 0,1,2,3,4
p,q,n stay the same.

Add each probability you calculate for the total probability.

For (c):

Add together the probabilities you calculated for (a) and (b). Then subtract that value from 1. This will be your answer for (c).

You could also use a binomial probability table to find the above probabilities as well. This would be easier than calculating each by hand.

I hope this will help get you started.