Question

Of the last 20 trains to arrive at Danville Station, 15 were on time. What is the experimental probability that the next train to arrive will be on time?
Write your answer as a fraction or whole number.
P(on time)=

Answer 1

The experimental probability \( P \) of an event is calculated using the formula:

\[
P(event) = \frac{\text{Number of successful outcomes}}{\text{Total number of trials}}
\]

In this case, the event is that a train arrives on time. From the information given:

- The number of successful outcomes (trains arriving on time) is 15.
- The total number of trials (total trains that arrived) is 20.

Thus, the experimental probability that the next train to arrive will be on time is:

\[
P(\text{on time}) = \frac{15}{20}
\]

We can simplify this fraction:

\[
P(\text{on time}) = \frac{15 \div 5}{20 \div 5} = \frac{3}{4}
\]

Therefore, the experimental probability that the next train will arrive on time is:

\[
\boxed{\frac{3}{4}}
\]