If the probability that an event will occur is $\frac{1}{5}$, then the probability that the event will not occur is $\frac{4}{5}$, and the odds in favor of the event occurring are The odds are $\square: \square$. (Simplify your answer.)

Step 1 ：The probability that an event will occur is given as \(\frac{1}{5}\).

Step 2 ：The probability that the event will not occur is therefore \(\frac{4}{5}\).

Step 3 ：The odds in favor of an event are defined as the ratio of the probability that the event will occur to the probability that the event will not occur.

Step 4 ：In this case, the odds in favor of the event occurring are \(\frac{1/5}{4/5}\).

Step 5 ：We can simplify this fraction by multiplying the numerator and the denominator by 5, which gives us \(\frac{1}{4}\).

Step 6 ：This means that for every 1 time the event occurs, we expect it to not occur 4 times.

Step 7 ：Final Answer: The odds in favor of the event occurring are \(\boxed{1:4}\).