News stories typically use statistics to enhance and add depth to the reader's understanding of the information presented. It's easy to take advantage of that once you have basic knowledge of common statistics and how they can be used. Percentages are used to describe the parts of a whole, the whole being one hundred. It is a proportional measurement. Let's look at the variable gender for an imaginary population.
Ratio just means the relation between two numbers.
The mean is nothing more than what we all call the average. It is used to summarize a group of numbers. For instance, the test scores from a certain class or incomes from a particular community. Yet that is not accurate to assume every time. In a test score example, a great many scores may be very high and a great many may be very low.