Final answer:
Comparing PC fonts to Mac fonts on websites cannot be generalized to a specific percentage difference as it varies based on several factors, including browser and operating system settings.
Step-by-step explanation:
The size of PC fonts being compared to Mac fonts on websites can be influenced by different factors including the browsers, the operating system's display settings, and how the website's CSS is coded. It is not accurate to say definitively that PC fonts are always a certain percentage larger or smaller than Mac fonts as it can depend on the specific circumstances. However, there might be a perceived difference in size due to the default rendering settings on different operating systems or the default font sizes set by the user's browser.