Hello!
The answer is:
Rachel swam
miles or 0.42 miles more than Jason.
Why?
To calculate how many miles did Rachel swim more than Jason, we need to write the following equation:

Where,
Difference, is equal to the number of Miles that Rachel did more than Jason
RachelMiles, is equal to 2 2/3rd miles plus 4.5 miles.
Jason Miles, is equal to 3.5 miles plus 3 1/4th miles.
Also, we need to remember the following:
- How to convert mixed fractions to improper fractions,

- How to add or subtract fractions and whole numbers.

Now, we are given the following information:
Jason's miles:

Rachel's miles:

Now, substituting the miles swam by Rachel and Jason into the equation, we have:

Hence, we found that Rachel swam 0.42 miles more than Jason.
Have a nice day!