Has anyone ever asked you "How sure are you?" and you replied "I'm 90% sure." Do you really know what this means? Perhaps you do, perhaps not... let's find out, shall we?
In our Applied Statistics class, we took the "Self-Test of Confidence". You can play along at home!
Self-Test of Confidence
For each of the following ten items, provide a low and high guess such that you are 90 percent sure the correct answer falls between the two. Your challenge is to be neither too narrow (i.e. overconfident) nor too wide (i.e. underconfident). If you successfully meet this challenge you should have 10 percent misses - that is, exactly one miss.
Example: if you were asked today's high temperature, your response should be "between X degrees and Y degrees", where X and Y vary depending on your weather. Here in Fontainebleau I would answer: "90% sure that today's high temperature was between 0 C and 15 C." Bon courage!!
1. Martin Luther King, Jr.'s age at death
2. Length of Nile River in kilometers
3. Number of member countries in OPEC
4. Number of books in Old Testament
5. Diameter of the Moon in kilometers
6. Weight of an empty Boeing 747 in kilograms
7. Year in which Wolfgang Amadeus Mozart was born
8. Gestation period (in days) of an Asian elephant
9. Air distance from London to Tokyo in kilometers
10. Deepest (known) point in the oceans in meters
Strictly speaking, this is a 10-times repeated Bernoulli trial giving a binomial distribution, but you probably don't need more details. You're probably looking for the answers, but do jot down your answers first. It only takes a few minutes, and it's really, really interesting. Remember: you need a lower and upper bound for each response.
OK OK, I know you just want the answers!!!
9:23:46 PM
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