To drive home the point from today's earlier post, let's give you How To Lie With Graphs 101:
Today's Exemplar: (A)
My Less Evil Twin, however, has told you a different story, using this graph: (B)
Which graph is worse?
It depends on how old you are!
So now, the poser for you, warmly ensconced in your Common Core cocoon of fuzzy math, because you're an English Major, taught only from the perspective of Writers Of Color, to avoid all that mathy racist White Supremacy:
Which one of us is fear-mongering, and lying our ass off?
a) A - me
b) B - my Less Evil Twin
c) Both of us
Bummer for you, it's a trick question.
The correct answer is technically d) neither one of us.
Because both graphs are actually true.
The better question is, which one represents reality better?
You can't answer that, until we give you graph (C), which shows you how much of the population makes up each of those brackets.
A) Makes it look like the elderly have a far higher risk of death from lycanthropy.
B) Lets you know far more people aged 45-54 than aged 85 and up are dying from it.
Neither is lying to you overtly, but A) lulls people into a false sense of security, and B) frightens those in the hardest hit bracket.
So both of us told you the truth, or at least some of it, and yet both of us used a graph to lie to you, because we weren't giving the truth, the whole truth, and nothing but the truth.
You can't do the math if the person setting up the problem doesn't give you the variables.
An honest graph would transparently break the demographic sections, not into pseudo-handy 10-year spans, but into timespans that would make each column on the graph the exact same size as it was of the actual population. That's apples-to-apples, and fair.
Just like there are two ways to slice a pizza into 4 slices for four people:
One example is fair and honest, and the other one is bullshit.
(If anyone can't grasp that, let's go out for pizza: you buy it, and I'll slice it and divvy it up.)
Crying "But I gave you one slice, and I cut it four ways, just like I promised!" for the second example is going to get your ass kicked by the two guys who get the little slices.
The same is true for making graphs that make one column look 15X bigger, then finding out it's bullshit.
This is why a shitty graph is always dirty pool, and why you need to understand math and use it to know when you're being lied to or bamboozled, just like you were taught to count money to teach you how to know someone making change is honest, or a cheat.
We yell because we care, and the internet is not the place to check your brains and believe everyone who says "Trust me. I teach statistics."