We are given a frequency table with the results of a survey showing the frequency of responses for number of siblings students have.
Number of Siblings
Frequency
0
5
1
12
2
15
3
7
A probability distribution shows the probability of each possible outcome. To find the probability distribution for the number of siblings, we will start by finding the total number of responses. To do so we will add the frequencies.
5+ 12+ 15+ 7= 39
Finally, we will write each frequency as a fraction of the total number of responses. This will give us the probability of each number of siblings of the surveyed students.
Number of Siblings
Frequency
Probability
0
5
5/39
1
12
12/39=4/13
2
15
15/39=5/13
3
7
7/39
We can now use our table to find the desired probability. Notice that if a student has more than 1 sibling, he or she can have 2 or 3 siblings, so we will add up these probabilities.
