Answer: There is probability of 46.9% that Erin will have a heart attack and the test predicts it.
Step-by-step explanation:
Since we have given that
Probability that her family had a risk of heart attack P(A)= 70%
Probability that the reliability of the stress test P(B)= 67%
Since events A and B are independent events.
so, we can apply the rule of independent events :
We need to find the probability that Erin will have a heart attack and the test predicts it .
![P(A\cap B)=P(A).P(B)\\\\P(A\cap B)=0.70\times 0.67\\\\P(A\cap B)=0.469\\\\P(A\cap B)=0.469\times 100\%\\\\P(A\cap B)=46.9\%](https://tex.z-dn.net/?f=P%28A%5Ccap%20B%29%3DP%28A%29.P%28B%29%5C%5C%5C%5CP%28A%5Ccap%20B%29%3D0.70%5Ctimes%200.67%5C%5C%5C%5CP%28A%5Ccap%20B%29%3D0.469%5C%5C%5C%5CP%28A%5Ccap%20B%29%3D0.469%5Ctimes%20100%5C%25%5C%5C%5C%5CP%28A%5Ccap%20B%29%3D46.9%5C%25)
Hence, there is probability of 46.9% that Erin will have a heart attack and the test predicts it.