Respuesta :
Solution: We are given:
Total students = 10 + 30 + 10 =50
Number of students who received A grade = 3 + 10 + 5 = 18
Number of senior student's who received A grade is = 10
Let A be the event that the student is senior and B be the event that he or she earned an A. Then,
[tex]P(A \cap B)=\frac{10}{50}[/tex]
[tex]P(B) = \frac{18}{50}[/tex]
Now the probability a student chosen at random from this class and is found to have earned an A, the probability that he or she is a senior is:
[tex]P(A|B) = \frac{P(A \cap B}{P(B)}[/tex]
[tex]=\frac{\frac{10}{50} }{\frac{18}{50} }[/tex]
[tex]=\frac{10}{18}=\frac{5}{9} =0.556[/tex]
Using the probability concept, it is found that there is a 0.5555 = 55.55% probability that he or she is a senior.
A probability is the number of desired outcomes divided by the number of total outcomes.
In this problem:
- 3 + 10 + 5 = 18 students received an a.
- Of those, 10 are seniors.
Then:
[tex]p = \frac{10}{18} = 0.5555[/tex]
0.5555 = 55.55% probability that he or she is a senior.
A similar problem is given at https://brainly.com/question/15536019
