probability and business statistics

Question

grades and gender

A B C TOTAL

MALE 6 20 14 40

FEMALE 8 10 9 27

TOTAL 14 30 23 67

d. If one student is chosen at random, find the probability that the student got a “B” GIVEN they are male

Answer 1

Since we are looking to find the probability that the student got a “B” GIVEN they are male, we will only look at the data for male (not female or total).

Looking at the data above, we see that 20 male students got a B. The total number of male students is 40.

The probability that a student got a "B" given they are male would be 20/40 or 1/2 simplified.

Answer 2

Let B = student got a B in the class and M = student is male

P(B l M) = P(B and M) / P(M) = (20 / 67) / (40/67) = 20 / 40 = 0.5

Answer 3

Number of males with a B / total number of students.