If the probability of a student taking a calculus class is 0.10, the probability of taking a statistics class is 0.90, and the probability of taking a calculus class and a statistics class is 0.07, what is the probability of a student taking a calculus class or a statistics class

Respuesta :

Answer:

93% probability of a student taking a calculus class or a statistics class

Step-by-step explanation:

We solve this problem building the Venn's diagram of these probabilities.

I am going to say that:

A is the probability that a student takes a calculus class.

B is the probability that a student takes a statistics class.

We have that:

[tex]A = a + (A \cap B)[/tex]

In which a is the probability that a student takes calculus but not statistics and [tex]A \cap B[/tex] is the probability that a student takes both these classes.

By the same logic, we have that:

[tex]B = b + (A \cap B)[/tex]

The probability of taking a calculus class and a statistics class is 0.07

This means that [tex]A \cap B = 0.07[/tex]

The probability of taking a statistics class is 0.90

This means that [tex]B = 0.9[/tex]. So

[tex]B = b + (A \cap B)[/tex]

[tex]0.9 = b + 0.07[/tex]

[tex]b = 0.83[/tex]

The probability of a student taking a calculus class is 0.10

This means that [tex]A = 0.1[/tex]

[tex]A = a + (A \cap B)[/tex]

[tex]0.1 = a + 0.07[/tex]

[tex]a = 0.03[/tex]

What is the probability of a student taking a calculus class or a statistics class

[tex]A \cup B = a + b + A \cap B = 0.03 + 0.83 + 0.07 = 0.93[/tex]

93% probability of a student taking a calculus class or a statistics class