Question

The number of births in the United States for a recent year indicated that there were 128,665 sets of twins, 7110 sets of triplets, 468 sets of quadruplets, and 85 sets of quintuplets. Choose one baby from these multiple births. What is the probability that the baby was a triplet?

Answer 1

OK, so since the twins are 2 babies
and triplets are 3 babies
and quadruplets are 4 babies

then the chance you get a quadruplet baby is higher than their relative
birth occurence, because they're double the babies!!

right?

so in fact, to get the chance of a triplet baby, you divide the number of
triplets*3 (three babies for every triplet) with
--------------------
(twins x 2
+triplets x 3
+quadruplets x 4
+quintuplets x5)

Answer 2

there is only 85 quintuplets, but they introduce 425 babies
so you have to multiply the 85 quintuplets with 5

Answer 3

I got it! It's .076! :)

Answer 4

I checked with the answer key, and this is the right answer. I was just confused on how to show my work. Thank you so much!

Answer 5

you're welcome!