The problem provides a volume of water: $321,000,000$ cubic miles. We are asked to find the percentage of total water that this volume represents. However, we need more information to solve for the percentage. We need the total volume of all water. Without this total volume, we cannot calculate the percentage. Let's assume the total volume of water is $T$.

1. Problem Description

The problem provides a volume of water: $321,000,000$ cubic miles. We are asked to find the percentage of total water that this volume represents. However, we need more information to solve for the percentage. We need the total volume of all water. Without this total volume, we cannot calculate the percentage. Let's assume the total volume of water is $T$.

2. Solution Steps

We are given a partial volume of water, say $V = 321,000,000$ cubic miles.

To calculate the percentage of this water relative to the total water $T$, we use the following formula:

$Percentage = \frac{V}{T} * 100$

Since we don't know $T$, we cannot compute the percentage. Let's assume that the total volume of water is $332,500,000$ cubic miles. Then:

$Percentage = \frac{321,000,000}{332,500,000} * 100$

$Percentage = \frac{321}{332.5} * 100$

$Percentage = 0.9654151376146789 * 100$

$Percentage = 96.54151376146789$

Without a given total volume $T$, we cannot compute the specific percentage of the provided volume.

3. Final Answer

The percentage of the given volume is dependent on the total volume of water, which is not provided in the problem. If we assume the total volume of water is $332,500,000$ cubic miles, then the percentage is approximately $96.54\%$.