To calculate the probability that a student chosen randomly from the class has a brother, we first need to find the total number of students that have a brother.
From the table, we can see that there are 13 students who have a brother and a sister, and 2 students who have a brother but not a sister. Therefore, the total number of students with a brother is 13 + 2 = 15.
Next, we need to find the total number of students in the class. Adding up all the values in the table, we get 13 + 11 + 2 + 4 = 30.
So, the probability that a student chosen randomly from the class has a brother is:
15 (number of students with a brother) / 30 (total number of students) = 0.5 or 50%
In a class of students, the following data table summarizes how many students have a brother or a sister. What is the probability that a student chosen randomly from the class has a brother?
Has a brother Does not have a brother
Has a sister 13 11
Does not have a sister 2 4
1 answer