Question

If left-handed people make up 15 percent of the general population, what is the probability that:

a) Of 21 Statics students, there will be 0 lefties;

b) Of 23 Engineering Analysis students, there will be 1 lefty.

Answer 1

Left handed people make up 15 % percent of the general population.

Let X denotes a random variable denoting the number of lefty people in a population.

(a) Of 21 statics students,there would be 0 lefties.

So,here

X~binomial(21,0.15)

P(X=0)

=(21 C 0)(0.15)⁰(0.85)²¹

=0.032

(b) Of 23 Engineering analysis students,there would be 1 lefty.

So,here

x~binomial(23,0.15)

P(X=1)

=(23 C 1)(0.15)¹(0.85)²²

=23*0.15*0.028

=0.097