**Calculating the Time to Complete the Race**

To determine the time it will take for the marathon runner to complete the race, we can use the given information that the runner covers a distance of 26 km in 1 hour.

We can set up a proportion to solve for the unknown time it will take to complete the entire race:

1 hour is to 26 km as X hours is to 26 km

Mathematically, this can be represented as:

1 hour / 26 km = X hours / 26 km

Simplifying the equation, we find:

1 = X

Therefore, it will take the marathon runner 1 hour to complete the race.

**Explanation:**

The given information states that the marathon runner runs 26 km in 1 hour. This means that the runner maintains a constant speed throughout the hour, covering a distance of 26 km.

Since the total distance of the race is also 26 km, we can conclude that the runner will complete the race in the same amount of time it takes to run 26 km, which is 1 hour.

It's important to note that this calculation assumes the runner maintains a consistent pace throughout the race. In reality, some factors such as fatigue, terrain, weather conditions, and race strategy may affect the runner's actual completion time. However, based on the given information, we can determine that the runner will take 1 hour to complete the race.

4 hours