The table shown lists the approximate new mutation rates for three autosomal dominant human diseases

Has anyone figured this one out yet?

Guessing that you can divide 20 by 106 = 0.1886.

0.1886 * 50000 = 9434 where born with this condition.

This is my guess...

Question:

Retinoblastoma = 20 mutations per 10^6 gametes
Achondroplasia = 80 mutations per 10^6 gametes
Neurofibromatosis = 220 mutations per 10^6 gametes

In a series of 50000 consecutive live births recorded in a large metropolitan area, how many new cases of each disease are expected?
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Answer:

Retinoblastoma = 2
Achondroplasia = 8
Neurofibromatosis = 22
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Explanation:

Divide the rate of each mutation by (10^6); and multiply by 50,000.  For example, Retinoblastoma has 20 mutations per 10^6 gametes.  20 / (10^6) = 2.00E^-5.  2.00E^-5 x 50,000 = 1.  Doing the same for Achondroplasia, you will get 4; doing the same for Neurofibromatosis will get you 11.  This is the rate of mutations per parent.  However, this question asks about "live births", and a live birth would require two gametes (one from each parent).  Thus, each number (1, 4, and 11) must be multiplied by two:

1 x 2 = 2
4 x 2 = 8
11 x 2 = 22

Hope this helps!

thank you so much!