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No. of girls in a family | 2 | 1 | 0 |
---|---|---|---|
No. of families | 475 | 814 | 211 |
Answer :
Total number of family = 475 + 814 + 211 = 1500
i) number of families of 2 girls = 475
So, we get that,
P1 =\( \frac{Number of families having 2 girls}{Total number of family}\)
p =\( \frac{475}{1500} = \frac{19}{60}\).
Therefore, the probability of a family, chosen at random, is having 2 girls
ii) Number of families having 1 girl = 814
So, we get that,
P2 = \( \frac{Number of families having 1 girls}{Total number of family}\)
p = \(\frac{814}{1500} = \frac{407}{750}\)..
Therefore, the probability of a family, chosen at random, is having 2 girls
iii) Number of families having no girl = 211
So, we get that,
\(P3 = \frac{Number of families having 0 girls}{Total number of family}\)
\(p = \frac{211}{1500}\).
Therefore, the probability of a family, chosen at random, is having 2 girls
Now, Sum of all these probabilities
= P1 + P2 + P3
= \(\frac{19}{60} + \frac{407}{750} + \frac{211}{1500}\)
\(= \frac{475 + 814 + 211}{1500}\)
\(= \frac{1500}{1500} = 1\)
Hence, we can say that,
The sum of these probabilities is 1.