MMM #22: The Grinch Bug at Blinkdagger
December 22nd, 2008 | by Sol |Blinkdagger has posted the latest Monday Math Madness problem!
Here’s the problem. Check out the rules and submission info at Bllinkdagger.
I got extremely sick and was wondering if I got a weird virus. I heard there was this Grinch Bug going around. Making you sick throughout Christmas Holiday. I decided to go check it out. The doctor told me their test measurements are 99 percent accurate (regardless if results are positive or negative). This Grinch Bug only occur randomly in the population (assume infected people are independent and distributed evenly), around 1 in every 10,000 people. He told me not to worry.
Today I got the report. It came out positive! What are the chances I actually have the disease? Should I be worried?
Happy Holidays to everyone!
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One Response to “MMM #22: The Grinch Bug at Blinkdagger”
By notedscholar on Dec 24, 2008 | Reply
This whole problem is based on a false premise.
It assumes standard probability theory, which is now defunct. In reality the chances can be expressed in a strict disjunctive sentence, i.e. P(test measurements being accurate) = 0 v 100%.
Nice try on the trick question though.
NS
http://sciencedefeated.wordpress.com/