Math Problem Statement

Giving a test to a group of students, the table below summarizes the grade earned by gender.

A	B	C	Total

Male 12 19 2 33 Female 14 16 15 45 Total 26 35 17 78

If one student is chosen at random, find the probability that the student is male given the student earned grade B. Round your answer to four decimal places.

Solution

The problem is asking for the probability that a randomly chosen student is male, given that the student earned a grade of B. This is a conditional probability problem.

The formula for conditional probability is:

P(Male | Grade B)=P(Male and Grade B)P(Grade B)P(\text{Male | Grade B}) = \frac{P(\text{Male and Grade B})}{P(\text{Grade B})}

From the table, we can extract the necessary information:

  • P(Male and Grade B): This is the number of male students who earned a B, which is 19.
  • P(Grade B): This is the total number of students who earned a B, which is 35.

Now, we calculate the conditional probability:

P(Male | Grade B)=1935P(\text{Male | Grade B}) = \frac{19}{35}

Next, we compute the value and round to four decimal places:

P(Male | Grade B)=0.5429P(\text{Male | Grade B}) = 0.5429

Thus, the probability that a randomly chosen student is male given that they earned a grade of B is 0.5429.

Would you like further details on this, or do you have any questions?


Here are 5 related questions to expand on the concept:

  1. What is the probability that a randomly chosen student earned grade B given they are female?
  2. What is the probability that a randomly chosen student is female given that the student earned grade C?
  3. What is the total probability that a randomly chosen student earned an A?
  4. How would the probability change if more male students had earned grade C?
  5. How do we calculate the probability that a student is female and earned an A?

Tip: Always make sure to carefully distinguish between joint probabilities (both events happening) and conditional probabilities (one event given another).

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Math Problem Analysis

Mathematical Concepts

Probability
Conditional Probability

Formulas

P(Male | Grade B) = P(Male and Grade B) / P(Grade B)

Theorems

Conditional Probability Theorem

Suitable Grade Level

Grades 9-12