Heart failures are due to either natural occurrences (87%) or outside factors (13%). outside factors are related to induced substances (73%) or foreign objects (27%). natural occurrences are caused by arterial blockage (56%), disease (27%), and infection (e.g., staph infection) (17%) determine the probability that a failure is due to induced substance.(b) determine the probability that a failure is due to disease or infection.

(a) The probability is 9.49%

(b) The probability is 38.28%

Step-by-step 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%