We know that,
If odds in favor of the occurrence an event are a:b, then the probability of an event to occur is \(\frac{a}{a+b}\), similarly, if odds are not in the favor of the occurrence an event are a:b, then the probability of not occurrence of the event is \(\frac{a}{a+b}\)
We also know that,
Probability of occurring = 1 - the probability of not occurring
= \(1-\frac{a}{a+b}\)
= \(\frac{b}{a+b}\)
Given a = 4 and b = 7
Probability of occurrence = \(\frac{7}{4+7}\) = \(\frac{7}{11}\)
Conclusion: Probability that the event occurs is \(\frac{7}{11}\)