At its simplest, in the West we have a thing for threes. Three bits of God, three little pigs, three branches of government (in the USA at least), "things come in threes", three books/movies in a series (a trilogy), stories that have a "beginning/middle/end".
Bottom line, the West tends toward organizing and thinking of things in threes. Some might even be superstitious about threes (perhaps a Pythagorean influence).
In China the number 4 plays a similar role. I don't know much about 'numerology' in China, save to say that recently the number 4 (which apparently sounds like 'death' in Chinese) has been considered bad luck. Here's a better explanation than I could give: https://www.quora.com/In-Chinese-culture-why-is-the-number-4...
4 seasons, the 4 corners of the world, the 4 cardinal directions, the 4 bodily humors (https://en.wikipedia.org/wiki/Humorism), you can find a ton of 4's in the West.
In Hong Kong, "Chinese" buildings skip floor 4, 14, ..., while "Western" buildings skip floor 13. More recent culturally inclusive buildings skip floors 4, 13, 14, ... The most prestigious floors are 8 and 88.
To add a complication, Chinese tends to use the US convention (with the ground floor being floor 1), while the English convention is the British one (with the ground floor being floor 0).
By happy coincidence, then, the 13th floor is also 十四樓, ie the 14th floor, so you only need to skip one floor, rather than two. That explains why HK skyscrapers are so high.
3 is important in decision making because it makes it easier to form a consensus. If I disagree with your idea, you have another entity to act as an arbiter.
