Question

A wildlife biologist examines frogs for a genetic trait he suspects may be linked to sensitivity to industrial toxins in the environment. Previous research had established that this trait is usually found in 1 of every 8 frogs. He collects and examines a dozen frogs. If the frequency of the trait has not changed, what’s the probability he finds the trait in a) none of the 12 frogs? b) at least 2 frogs? c) 3 or 4 frogs? d) no more than 4 frogs?

Answer 1

Answer:

Step-by-step explanation:

given that a wildlife biologist examines frogs for a genetic trait he suspects may be linked to sensitivity to industrial toxins in the environment. Previous research had established that this trait is usually found in 1 of every 8 frogs

Thus no of frogs which have the trait X is binomial since each frog is independent of the other with constant probability = 1/8 = 0.125

n = 12

a) P(X=0) = $(0.875)^{12} \\=0.2014$

b) $P(X\geq 2)\\= 0.4533$

c) P(x=3)+P(x=4)

= 0.1707

d) $P(X\leq 4)\\= 0.9887$