a survey found the distribution of some families by size, and is as follows.\nfamily size 2 3 4 5 6 7…

a survey found the distribution of some families by size, and is as follows.\nfamily size 2 3 4 5 6 7 8\nfrequency 87 50 61 31 16 3 2\nfind the probability of family with 3 people.\np(3) = ?
Answer
Explanation:
Step1: Calculate total frequency
$87 + 50+61 + 31+16+3+2=250$
Step2: Calculate probability
The frequency of families with 3 people is 50. Probability $P(3)=\frac{\text{Frequency of 3 - person families}}{\text{Total frequency}}=\frac{50}{250}$
Answer:
$\frac{50}{250}=0.2$