Answer:
Around 7.6%
Step-by-step explanation:
First, keep this in mind:

If we divide 1/10, we get 0.1, however to get it in % we need to multiply by 100.
Number of people who use computers: 25,800
Number of people in total: 340,000
To find how big that "part" (number of people who use computers), we need to divide it with the "whole" (number of people in the town):
Part / Whole

Now, multiply it by 100 to get it in %
≈ 7.6%
Answer: around 7.6%