In addition to the blood types A, B, AB , and O, a person’s blood may be classified as Rh positive or Rh negative. In the United States, about 15% of the white population is Rh negative, while the percent is much lower in other racial groups. The director of a blood bank wants to estimate the probability that in a random group of 50 unrelated white donors, at least 8 will have Rh negative blood. If she generates random numbers to simulate this problem, how could she assign the numbers to the two blood types?

The answer is D

To assign the random numbers to the two blood types (Rh positive or Rh negative), the director of the blood bank could follow these steps:

Step 1: Define the coding system:
- Assign a numerical value to Rh positive blood, for example, 1.
- Assign a numerical value to Rh negative blood, for example, 0.

Step 2: Generate random numbers:
- Using a random number generator, the director can generate a set of 50 random numbers within a desired range. Let's assume the range is between 0 and 1, inclusive.
- These random numbers will represent the blood types of the donors in the random group.

Step 3: Assign the random numbers to the blood types:
- For each of the 50 random numbers generated, if the number is greater than or equal to 0.15 (since 15% of the white population is Rh negative), the donor will be assigned Rh positive blood (coded as 1).
- If the random number is less than 0.15, the donor will be assigned Rh negative blood (coded as 0).

Step 4: Count the number of Rh negative donors:
- Count the number of donors in the random group that have been assigned Rh negative blood (coded as 0).
- Let's say the count is denoted as "X."

Step 5: Calculate the probability:
- The director can estimate the probability of having at least 8 donors with Rh negative blood by calculating the probability of X being greater than or equal to 8.
- This probability can be computed using various statistical methods, such as binomial distribution or simulation.

By following these steps, the director can assign the random numbers to the two blood types (Rh positive or Rh negative) and estimate the probability of having at least 8 donors with Rh negative blood in a random group of 50 unrelated white donors.