IDNLearn.com makes it easy to find accurate answers to your specific questions. Find the solutions you need quickly and accurately with help from our knowledgeable community.

This week in school, there is a 75% probability of having a fire drill, a 50% probability of a tornado drill, and a 25% probability of having both drills. Let event [tex]\( F \)[/tex] be a fire drill and event [tex]\( T \)[/tex] be a tornado drill. Are the two events independent?

A. No, because [tex]\( P(F \cap T) \neq P(F) \cdot P(T) \)[/tex].
B. No, because [tex]\( P(F \cap T) \neq P(F) + P(T) \)[/tex].
C. Yes, because [tex]\( P(F \cap T) = P(F) \cdot P(T) \)[/tex].
D. Yes, because [tex]\( P(F) = P(T) + P(F \cap T) \)[/tex].


Sagot :

To determine if the events [tex]\( F \)[/tex] (fire drill) and [tex]\( T \)[/tex] (tornado drill) are independent, we need to check if the probability of both events occurring simultaneously, [tex]\( P(F \cap T) \)[/tex], equals the product of the individual probabilities of each event, [tex]\( P(F) \cdot P(T) \)[/tex].

Here are the given probabilities:
- [tex]\( P(F) = 0.75 \)[/tex]
- [tex]\( P(T) = 0.5 \)[/tex]
- [tex]\( P(F \cap T) = 0.25 \)[/tex]

First, let's calculate the product of [tex]\( P(F) \)[/tex] and [tex]\( P(T) \)[/tex]:
[tex]\[ P(F) \cdot P(T) = 0.75 \cdot 0.5 = 0.375 \][/tex]

Next, we will compare [tex]\( P(F \cap T) \)[/tex] with [tex]\( P(F) \cdot P(T) \)[/tex]:
[tex]\[ P(F \cap T) = 0.25 \][/tex]
[tex]\[ P(F) \cdot P(T) = 0.375 \][/tex]

Since [tex]\( P(F \cap T) \neq P(F) \cdot P(T) \)[/tex], the two events are not independent. Therefore, the correct answer is:

No, because [tex]\( P(F \cap T) \neq P(F) \cdot P(T) \)[/tex].