Certainly! Let's work through the question step-by-step.
First, we need to determine the overall probability that a single randomly chosen U.S. resident has type O blood. The blood types O+ (O positive) and O- (O negative) both fall under type O blood.
From the table, we have the following probabilities:
- Probability of O+ (O positive): 0.374
- Probability of O- (O negative): 0.066
To get the total probability of a person having type O blood, we add these two probabilities together:
[tex]\[ \text{Probability of type O blood} = \text{Probability of O+} + \text{Probability of O-} \][/tex]
[tex]\[ = 0.374 + 0.066 \][/tex]
[tex]\[ = 0.44 \][/tex]
Next, we need to find the probability that two randomly chosen U.S. residents both have type O blood. Since the events are independent (the blood type of the first person does not affect the blood type of the second person), we multiply the probability of each independent event:
[tex]\[ \text{Probability that both have type O blood} = (\text{Probability of type O}) \times (\text{Probability of type O}) \][/tex]
[tex]\[ = 0.44 \times 0.44 \][/tex]
[tex]\[ = 0.1936 \][/tex]
Finally, to express this probability as a percentage, we multiply by 100:
[tex]\[ \text{Percentage} = 0.1936 \times 100 \][/tex]
[tex]\[ = 19.36 \% \][/tex]
Therefore, the probability that two randomly chosen U.S. residents both have type O blood is [tex]\(19.36\%\)[/tex]. So the correct answer is:
[tex]\[ \boxed{19.36 \%} \][/tex]
