To determine the fraction of the 300 fish that Nita caught, first, we determine the number of fish that Chris caught. The 45% of 300 is:

Now, in total Chris, Nita and Craig caught 300 fish, therefore:

x represents the number of fish caught by Nita.
Solving the above equation for x, we get:

Therefore, Nina caught

out of the 300 fish, which is represented by the fraction:

Finally, simplifying the above fraction, we get:

Answer:
