Question

the table below gives the probability density for blood types in a population.

if a person is selected at random, what is the probability that their blood type is o or b?

Explanation:

Step1: Identify probabilities

The probability of blood type O is \(P(O) = 0.49\), and the probability of blood type B is \(P(B)=0.20\).

Step2: Use addition rule for mutually - exclusive events

Since a person cannot have both blood type O and B simultaneously (mutually - exclusive events), the formula \(P(A\cup B)=P(A)+P(B)\) is used. Here \(A = O\) and \(B = B\), so \(P(O\cup B)=P(O)+P(B)\).
Substitute the values: \(P(O\cup B)=0.49 + 0.20\).

Answer:

\(0.69\)