Answer:
(a) The probability is 9.49%
(b) The probability is 38.28%
Explanation:
The probability that a failure is due to induced substance is calculated as a multiplication as:
(13%) * (73%) = 9.49%
Where 13% is the percentage of heart failures that are due outside factors and 73% is the percentage of outside factors that are due induced substances.
On the other hand, the probability that a failure is due to disease or infection is the sum of the probability that a failure is due to disease and the probability that a failure is due to infection.
Then, the probability that a failure is due to disease is calculated as:
(87%) * (27%) = 23.49%
Where 87% is the percentage of heart failures that are due natural factors and 27% is the percentage of natural factors that are due disease.
At the same way, the probability that a failure is due to infection is calculated as:
(87%) * (17%) = 14.79%
So, the probability that a failure is due to disease or infection is:
23.49% + 14.79% = 38.28%