Do you recognize CREATIVE AND MISLEADING MATH?

[AviatorTom]

Can you see what is wrong with this...

Researchers compared two popular weight loss drugs in a head-to-head trial for the first time, and Drug A won. Drug A helped participants lose an average of 20.2% of their body weight in 18 months, compared to Drug B, which led to 13.7% weight loss on average for its test group in the same time period. That means the Drug A group patients lost 47% more weight than those in the Drug B group.

It's called Creative and Misleading Math, typically done to intentionally mislead the reader.

If you don't see the error in this, tune in tomorrow, when an explanation will be given.

Updates

1 y

The error is taking a percentage difference of the percentages. Let's say two people each weigh 100 pounds. Person A takes Drug A and loses 20% of their weight, so they now weigh 80 pounds. Person B takes Drug B and loses 14% of their weight, so they now weigh 86 pounds. That's a 6 pound difference, or about 7% more weight loss for Person A/Drug A, not 47%.

[purplepoppy]

What grinds my gears is when people mix fractions and percentages in the same statement. John lost 1/3 Mary gained a quarter but Tom gained 33%. Don't get me started on people who mix up units

If you want a real life example of math so creative it could have come from a Hogwarts math lesson try our governments logic

The speed limit has dropped from 30 to 20
Eg by 33% or a third.
Hence a journey should take 33% longer.
But according to government maths all journeys are only an average of 1 min more.

[AviatorTom]

@purplepoppy Excellent point. My guess is that the government is assuming a 3-minute journey, which will now take 4 minutes. See... the government is not totally wrong. 🙈🙉🙊

[juliammm]

(20.2 - 13.7)/13.7 => 47%

It gives a 47% of the ratio.

But in reality

Group A lost 20.2

Group B lost 13.7

Group A lost (20.2 - 13.7)=6.5 more than group B

[Astarlessnightsky]

Its not the math thats creative and misleading. Its just math, nothing more and nothing less.

What can be misleading is the way its presented, eg in a graph with two different units on the y axis, or cherry picking which information you want to mainly publish.

[OlderAndWiser]

Applied math is a strong suit for me so I immediately recognize the misleading nature of the calculations. Or, as my father often said, “liars figure and figures lie.”

[OlderAndWiser]

Thanks for MHO!

[Graptemys79]

There could be a problem conflating mean (average) with median.