Using conditional probability, it is found that:
a. 39% of students in this sample was female.
b. 64.1% probability that she is a business major.
Conditional probability is the probability of one event happening, considering a previous event. The formula is:
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]
In which
Item a:
The proportion associated with female students is given by:
Hence:
P(A) = 0.5(0.5) + 0.25(0.4) + 0.4(0.1) = 0.39.
0.39 = 39% of students in this sample was female.
Item b:
The events related to the conditional probability are:
Hence:
[tex]P(A \cap B) = 0.5(0.5) = 0.25[/tex]
And the conditional probability is:
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.25}{0.39} = 0.641[/tex]
0.641 = 64.1% probability that she is a business major.
You can learn more about conditional probability at https://brainly.com/question/14398287