Grammar Moses: This is an average, meaning there will be math

By Jim Baumann

jbaumann@dailyherald.com

As surely as the sun rises and sets and President Trump takes to Twitter, I will find a way to introduce math into this column.

Indulge my personal therapy session. I'm one of those left-brain/right-brain people whose head might explode if I can't exercise both hemispheres at once.

For today's conversation, I dipped into my limited knowledge of statistics and immediately broke into a flashback about the insane world of differential equations.

Reader Jamie Smith took umbrage with the wording of our recent story about the likelihood of an early snow.

Our reporter last week wrote: "As for actual accumulation, Nov. 17 is the usual date for the first accumulation of a tenth of an inch or more."

I read that sentence and asked myself why we would use one five-syllable word twice in the same sentence.

But that was not reader Jamie's Smith's point in writing to me.

"It is usual for it to turn colder in late October. The average first date to see snow flurries is October. And the average first date of measurable snowfall is Nov. 17," she wrote in arguing against our use of "usual" instead of "average."

I'm not losing a lot of sleep over this one, but you know my capacity for hashing out the most piffling ponderings.

I am unconvinced that "average" is the right word to describe a date.

You can have an average day, meaning it is a day like many others.

"Usual" is defined as "habitually or typically occurring or done; customary." To my way of thinking, that makes "usual" a pretty good fit.

Clearly when someone decided Nov. 17 was the "average" day for the first measurable snowfall in the Chicago area, some sort of math was employed.

And here is where the math comes in.

To get an average, you need to add up several quantities and divide the number of said quantities.

Dates are not quantities.

In school I learned about three types of averages: mean, median and mode.

"Mean" is the type of average I just mentioned. "Median" is the point in the middle of a range of values. And "mode" is the most often occurring value in a group of quantities.

If you don't like "usual" and I don't like "average," can we settle on describing it as the "modal date"?

That seems the most accurate way to portray Nov. 17 in the sentence.

But then people would look at you strangely and say, "What are you talking about? You're probably the kind of person who would use 'piffling' in conversation."

Fun with percentages

If you believe a basketball player can put 110 percent of himself into a game, then you deserve to pay the price of a ticket.

"Is 100 percent meant to be a measure of all total?" inquired reader Don Grossnickle. "Stats are passed around with mixing percents. What are the correct and justified uses of multiple percents? For instance, there is a 3,000-percent increase in revenue coming from the sale of prepared foods tax income since 1959 in Arlington Heights."

Don, if you double something, you increase it by 100 percent. That is, you've increased it by the whole amount (100 percent) of what you already had.

If you triple something, you increase it by 200 percent, meaning you've increased it by two times what you originally had.

If you spent $2,000 on your first car and $50,000 on your latest one, you spent 2,400 percent more on your new ride. And with the exception of FM radio, air conditioning and power steering, I'll bet you still love your first car more.

Write carefully!

• Jim Baumann is vice president/managing editor of the Daily Herald. Write him at jbaumann@dailyherald.com. Put Grammar Moses in the subject line. You also can friend or follow Jim at facebook.com/baumannjim.