Question

According to data from the state blood program, 40 percent of all individuals have group a blood. if six individuals give blood, find the mean number of individuals having group a blood.

Answer 1

The mean number of individuals having group a blood is 2.4 individuals.

Step-by-step explanation:

We can solve this problem using concepts of the binomial probability distribution.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability. Has a mean of

`E(X) = np`

In this problem, we have that

40 percent of all individuals have group a blood. This means that
`p = 0.4`.

If six individuals give blood, find the mean number of individuals having group a blood.

We work with six individuals, so
`n = 6`.

The mean is:

`E(X) = np = 6*0.4 = 2.4`

The mean number of individuals having group a blood is 2.4 individuals.

Answer 2

Let's suppose that these six individuals are a representative sample from the population.

So to figure out this we can calculate 40% of 6, which is 2.4 individual.

So 2.4 individual from the six may have A blood group (you can keep the number as it is, or round to 2).