Question

Refer to the following information on full-term births in the United States over a given period of time.

Type of Birth	Number of Births
Single birth	45,500,000
Twins	200,000
Triplets	2000
Quadruplets	150

Use this information to estimate the probabilities of the following events.

(a) A randomly selected pregnant woman who reaches full term delivers twins. (Give the answer to three significant figures.)

(c) A randomly selected pregnant woman who reaches full term gives birth to more than a single child. (Give the answer to three significant figures.)

Answer 1

Answer:

Given that

Type of Birth	Number of Births
Single birth	45,500,000
Twins	200,000
Triplets	2000
Quadruplets	150

Total number of births = 45,500,000+ 200,000+ 2000+ 150

= 45,702,150

(a) A randomly selected pregnant woman who reaches full term delivers twins.

Answer:

P(twins) = 200,000/ 45,702,150

P(twins) = 0.0044

P(twins) = 0.004

Therefore the required probability is 0.004

(c) A randomly selected pregnant woman who reaches full term gives birth to more than a single child.

Answer:

Here

P(triplets) = 2000/ 45,702,150

P(triplets) = 0.000044

Now,

P(quadruplets) = 150/ 45,702,150

P(quadruplets) =  0.0000033

Now to find the Probability of more than a single child:

P(more than a single child) = P(twins) + P(triplets) + P(quadruplets)

P(more than a single child) =  0.0044 +0.000044 + 0.0000033

= 0.00445

P(more than a single child) = 0.004

Therefore the required probability is 0.004