Scientific accuracy and discrepancies

Can someone tell us what the correct use is of the terms figures, numbers, amount of, count and how many? These terms have different meanings.

The following phrases are often heard in the media and everyday speech, but what exactly do they mean?

What does "three doubled” actually mean? and, double more ; two times more than ; three times less than ; double less? (more or less !? ) ; or “growth of less than 10% ”?

The problem is in inaccurate language. All these examples actually boil down to the same thing, which only makes it worse if you ask me.

Well known also there is always misunderstandings too of a “billion”, in America it is a thousand million, and in England it is a million million. If I have it right. And then of course what is a trillion? This story is definitely confusing. America lives in a world of its own.

-

The financial experts say compound interest is the 8th wonder of the world but there is another, a curse of arithmetic.

For example “the stock price fell by 5%” or “increased 10%“ sounds in order, but an increase of 20% of 300 followed decrease of 20% is not obvious. If R300 increases by 20% and then decreases by 20% the result is not R300, in fact it would have decreased to ( (300 + 20% ) - 20% ) = 360 – 20% =  R288 (using poor notation) and it has lost R12.

This directly applies to the stock markets and repeated application leads to a decreasing stock price. Of course it is not as simple, taking devaluation of the current currency into account considering such as inflation, but still it doesn't look as if it can make up the difference, not with prices fluctuating every day.

This kind of calculation probably affects the prime lending rate when speaking of .25 or .5 “basis points” increase or decrease and such. I can only speculate, but what is a “basis point”? What then the “base”?

-

The word “average” in common use is unclear and in effect as is, scientifically speaking basically meaningless. For example, what is "the average man / person”? “life expectancy” ; “average temperature"? ; “30% chance of rain” ; “average yearly rainfall" and so on. In other words my question is how do you calculate it? The old “figures lie and liars figure”. 

They say that statistically it is safer to travel by passenger aircraft than motorcar, but how do they work it out? By time traveled or by distance covered? My bet it is calculated by time. The difference might be drastic, in which case it can be very misleading. You should be able to obtain reliable representative figures and work out estimates from that.
-

In practice, “he uses statistics like a drunken man uses lamp-posts – for support rather than illumination”.