Friday, November 13, 2009

Fun with Statistics!

No really, I actually do have fun with statistics. I am not a math person, I've never been a math person, to me, math is some sort of magical stuff that is beyond comprehension. EXCEPT...for statistics. I can't explain why it's different to me, it just is. I'm sure it has nothing to do with the topic of this book:

So the other day it occurred to me to find out what percentage in my family files I had of births of twins. No reason other than curiosity.

My maternal family tree database has 7,417 people in it. So I did an export of people and their birth dates to a .csv file and merely eliminated all those people who didn't have the same birthdate. What I found was this:

No instances of triplets.

27 sets of twins, which of course is 54 people.

I then eliminated those that were not a direct relation of mine and that took it down to:

25 sets of twins, 50 people.

That means the incidence of twins in my maternal family datebase is: 0.006741.

Not very high! Somehow when I entered those sets of twins I felt like it had been higher....

I then divided it by century to see how many sets of twins had been born per century:

1600s: 7

1700s: 9

1800s: 7

1900s: 2

And I wonder what happened in the last century to make it suddenly drop off! I blame incomplete data.

Interestingly, the 2 sets of twins born in the 1900s were both born in 1913 (May and October), one being on my maternal grandfather's side and the other being on my maternal grandmother's side.

Looking at gender, it's pretty even, 24 female and 26 male.

The closest to me when it comes to relationships are the 2 sets born in the 1900s, both of which are my great-grand aunt's and uncle's. Of the 25 sets of twins, 18 sets are some sort of cousins to me, with the remaining 7 being some sort of aunt or uncle.

And that completes my funtime with statistics for the day!

1 comment:

  1. Hmmm - I sense a future SNGF topic.... Wonder if I can do this with my database.