To find out how long it would take for the dolphin to swim 45 nautical miles at a speed of 25 knots, we can use the formula:
\[
\text{time} = \frac{\text{distance}}{\text{speed}}
\]
In this case:
- Distance = 45 nautical miles
- Speed = 25 knots
Now, we need to make sure the units are consistent. The speed of 25 knots is already in nautical miles per hour, since 1 knot = 1 nautical mile per hour. This means we don't need to change the units of speed, but we can see if the distance needs to be in the same unit.
### Calculation:
1. We insert the values into the time formula:
\[
\text{time} = \frac{45 \text{ nautical miles}}{25 \text{ knots}}
\]
2. Since knots means nautical miles per hour, we can directly perform the calculation:
\[
\text{time} = \frac{45}{25} = 1.8 \text{ hours}
\]
### Conclusion:
Since knots is expressed in nautical miles per hour and we have the distance in nautical miles, we can see that we don’t need to convert anything. So, we have verified that all units make sense.
Now, to fill in the blank regarding what needs to be converted, since the distance measured in nautical miles matches the speed measured in knots, we don’t really need to convert the units for either distance or speed—they are compatible.
Therefore, the answer would be:
\[
\text{I would need to convert the units of distance from knots to Option #2: nautical miles.}
\]
So, the final statement would be:
**Option #2: nautical miles**.
There’s no need to convert, but if it was required in a different scenario, it should be in nautical miles, which is already what we have!