Final answer:
20% of the people tested positive for disease x in the medical test of 500 people.
Step-by-step explanation:
To determine the percentage of people who tested positive for disease x, divide the number of people who suffer from the disease by the total number of people tested and then multiply by 100 to convert to a percentage.
Here's the calculation:
(100 people with disease x / 500 total people tested) × 100 = 20%
So, 20% of the people tested positive for disease x.
The correct answer from the given options is 2) 20%.