That, to your left, is detective-turn-teacher Roland “Prezbo” Pryzbylewski from HBO’s The Wire. If you have seen The Wire, then you know the phrase “jukin’ the stats”. If not, rent it, buy it, steal it, do whatever you have to do to see it because you’ve missed out on one of the greatest dramas ever to grace a TV screen. In short, The Wire is all about Baltimore in the early 2000s and is centered around Baltimore crime, police work, and city politics.
One of the recurring themes in the show is the phrase “jukin’ the stats” which is how the police manipulate the numbers to make crime rates appear to go down. Now, I know I’ve gone far off field so I’m going to bring this back to engineers and engineering. As engineers, we tend to be very good at everyday math. Also, we probably like our data to be presented in clear, concise formats and easily read charts. Thus, we’re generally good at seeing when stats have been juked for us. Or if I expand it slightly, we can spot when people think we can’t do simple math and we can spot when other people can’t do math. I’ve actually had a few of these issues recently so this is why it comes to mind.
Now, I know the basic one that most people deal with on a daily basis is getting change from a store clerk. You buy something that’s $6.87, you hand them $20 and wait for your $13.13 back. But often times, you’ll get $13.23. Or, they’ll forget you gave them $20 and only give you $3.13 back. That’s pretty annoying but easily corrected. Generally, it’s on fairly small amounts so you don’t have worry too much.
Quick changing is a different story. If you’ve worked in retail, one thing you might have come across is being quick changed, which is when someone pays cash for something and then proceeds to ask you to break bills for them. For instance, they buy something for $14.37 and pay with a $100 bill. So you shell out $85.63 in four $20s, one $5, and some coins. But then they ask you to break a $20 into two $5s and a $10. And then the $10 into ten $1s. And by that point, they expect you to forget that you gave them the $87 and change back. So they hold out the two $5s and the ten $1s and coins (with $60 hidden underneath) and say “you only broke the $20, I still need the $60”. So you shrug and hand out $60. This happens in all sorts of forms, but it’s all similar to that. I’ve seen it happen to a colleague when I worked at the mall and the quick change artist was out of the store in less than a minute with about 80 bucks before I could make it to the register. I’ve had it tried on me a few times, but now that I’m not in retail any more, I don’t worry about this one.
Another juked stat that comes up fairly often is risk assessment. For instance, DrWife and I were shopping for a new car seat for NanoGEARS. And the statistics say that toddlers are 80% safer when seated in the rear seats and backwards facing. And like most parents, we fret and try to make sure we’re doing things safely for our child. But the engineer in me asks how much safer is 80%? Are we talking about 5 in 100,000 chance of dying versus 9 in 100,000 chance of dying? In both cases, you probably don’t have much to worry about. But you wouldn’t know that unless you were given the raw data to make those assumptions. As an engineer, I want that raw data. But you can never seem to find it. My guess is they are afraid that people will dig into the fallacy of their statements.
The last example of a juked stat/numbers FUBAR/totally moronic person is something from my UG days. I worked at a store at the local mall, making ends meet. One day, the manager quits because he got a new job. Even though I was the only other full time worker, I didn’t have seniority, so they bumped up another part-time worker with seniority to a temp manager until the owner could find a new permanent manager. After a few months, I started to notice a change in my paychecks because of some slight accounting errors. So, one week, I asked if I could assist. The TempMGR went through the hours and numbers for the workers. Then I did. And they didn’t match. And it’s not like they were within round off error. They were about, at a guess, 40% off. Let me give you some background before I get to the twist.
We clocked in and rounded off minutes to the nearest 15 minutes. So if you work 45 hours and 15 minutes (pretty typical for my week), you worked a total of 2715 minutes for the week and your sheet would only show the number of minutes you work. If you made $8/hr, you’d divide 2715 by 60 and then multiply by $8; that would be a cool $362 for that week (forget overtime for now, waaaaaaay above TempMGR’s head).
Sadly, switching from minutes to hours was over TempMGR’s head as well. To get the number of hours worked, TempMGR did 2715/100 * $8….which is $217.20 and shockingly 40% off from $362!!!! TempMGR didn’t know that 60 minutes were in an hour?!?! How could that be?
I ranted. I yelled. I calmed down and explained nicely. Yet to no avail TempMGR insisted my math was wrong!! That was also the last thing we had to discuss as I promptly quit.
I know I’ve ranted before (most notably in my Fantasy Curriculum and my All out assault on math!) on how I dislike math for the sake of math. But this isn’t that. This is math for the sake of living. I know some of these examples I’ve discussed are more common and others (like the last one) are pretty rare. And, as awkward as it can be at times, I’m very glad and appreciative that I follow along with numbers games/scams/mistakes. It difficult pointing out other peoples’ mistakes, if they are indeed genuine mistakes. We’ve all dealt with that. However, I am curious when it hasn’t been a total mistake. I’d like to know some of the situations you’ve been in when someone has tested your math skillz and didn’t find you lacking.