Question

a genetic disease occurs in about 1 of every 3000 white births and about 1 of every 260,000 non - white births. if a gene of this disease is denoted with a c and a disease - free gene is denoted with a c (since the disorder is recessive), then only a cc person will actually have the disease. such persons would ordinarily die before parenting children, but a child can also inherit the disease from two cc parents (who themselves are healthy, that is, have no symptoms but are “carriers” of the disease). among 110,000 white births, about how many occurrences of the disease would you expect? one would expect the disease to occur in white births. (round to the nearest whole number as needed.)

Explanation:

Step1: Set up proportion

Let $x$ be the number of disease - occurrences among 110,000 white births. The proportion is $\frac{1}{3000}=\frac{x}{110000}$.

Step2: Cross - multiply

Cross - multiplying gives us $3000x = 110000$.

Step3: Solve for $x$

$x=\frac{110000}{3000}=\frac{110}{3}\approx37$.

Answer:

37