Question

This week in school, there is a 75 percent probability of having a fire drill, a 50 percent probability of a tornado drill, and a 25 percent probability of having both drills. Let event F be a fire drill and event T be a tornado drill. Are the two events independent?

Answer 1

For E2020 users, the correct answer is A (No,because P(F ∩ T) ≠ P(F) • P(T).)

Answer 2

Answer with Step-by-step explanation:

The events A and B are called independent if:

P(A∩B)=P(A)×P(B)

We are given that:

This week in school, there is a 75 percent probability of having a fire drill,

a 50 percent probability of a tornado drill,

and a 25 percent probability of having both drills.

Let event F be a fire drill and event T be a tornado drill.

P(F)=0.75

P(T)=0.50

P(F∩T)=0.25

P(F)×P(T)=0.375≠P(F∩T)

Hence, events F and T are not independent