Question

Suppose that you are in a class of 31 students and it is assumed that approximately 13% 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.
Answer .161

(b) Compute the probability that at most four students are left-handed.
Answer .129

(c) Compute the probability that at least six students are left-handed.
Answer .193

Answer 1

a. what is .13^5 * .87^(31-5) >

Put .13^5 * .87^(31-5)= in your google search window.

b. at most four students...
add the probabliliy of one, two, three, four, and none are left handed.
Pr=.13^0*.87^31+.13^1*.87^30 + ...

c. at least six?
that is the same as 1- probability5orless
= 1- Pr(a)-Pr (b) where pr(a), pr(b) is in part a, and b.

Answer 2

I worked this out like you said above and got (a)9.936 (b)9.955 and both of them were wrong, any suggestions????

Answer 3

where did you get .87 ?