Probability Enlightment
I did my dissertation using a Bayesian model and I am still proud of it. So I have been looking for chances to enlighten my daughter, who is in fourth grade. An opportunity presented itself the other day when I took Jessie to swimming practice. One of her teammates, say Amy, has 3 sisters who are also swimmers. It’s a small probability event perfect for an intro to probability. I started with the basics:
So Jessie, if some family is going to have a baby, what’s the chance of having a baby girl?
"A half," she said after a pause. I continued
Good. What’s the chance of having two baby girls?
"Em… Wait…" she continued after a long pause, "is it a quarter?" I was quite pleased.
Look at Amy’s family, they have 4 girls in a roll! What’s the chance of that?
I was so ready to explain to her why the answer is 1/16, when she quickly responded
One. ‘Cause it’s already happened.
April 4th, 2007 at 7:38 am e
You have to congratulate her on thinking outside the box though. A host of other people would have simply responded with 1/16.
April 13th, 2007 at 2:25 pm e
Smart kid!
I remember as a kid my dad asked me “you know how every one has parents: and they have ancestors too, and he drew this tree from me, to 2 parents, to 4 grand parents…
“Well” he said, “how does that end?”
I looked at the paper, then rotated it 180° and pushed it back to him. He smiled “yeah, not quite, but yeah”. We laughed.