In the United States 1,200 tornadoes a year kill 50 people. Texas has 149 tornadoes a year, Kansas has 93, and Oklahoma has 64. So Texas is the most dangerous place, right? That’s the deduction most people make, but a few of us know the importance of taking more things into consideration before drawing our conclusions.

What about the state’s Area?

Texas has .0005 tornadoes per square mile. Kansas has .0011 and Oklahoma, .0009, so Kansas is the most dangerous – right, Dorothy?

What about the state’s Population?

Texas has 23 million people, Kansas has 3 million, and Oklahoma, 4 million. On a per person basis, Texas has .00001 tornadoes, Kansas has .00003, and Oklahoma, .00002. So it looks like Kansas again, right?

So what’s the answer?

If the most dangerous state is the one with the largest number of tornado fatalities, it’s Mississippi, with 10 deaths per year. This also translates to .38 deaths per tornado, which is ten times worse than Texas (.05) , Kansas (.02), and Oklahoma (.04). There are at least five lessons here, and maybe more.

• Never assume we have all the data.
• Don’t be tricked by raw numbers.
• Calibrate numbers so we can compare them on equal footing.
• Determine which statistic is most useful.
• During analysis, always remind ourselves of the original question.