E^-5 = 10^-5

This is not the exponential function.

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- Jul 14th 2008, 10:23 AM #1

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## What does this mean??

An article discussing recidivism of juvenile prisoners between 14 and 17 years olld, indicating that 82% of those released were rearrested within 3 years. Solve the following problem for six newly released juvenile prisoners between 14 and 17.

a. Determine the probability that the number rearrested within 3 years will be exactly four; at least four; at most five; between two and five; inclusive.

I know how to figure out this problem, but I have a question. When I am trying to figure the probability of 0 being rearrested I use the formula

P(X=0) (6 0) 6!/0!(6-0)! (.82)^0(.18)^6

which I figure to be 1(.82)(.18)^6 my problem is, on my calculator it says 2.789002368E-5 what does this number mean? I get a similar answer with an E when figuring probability for 1.

- Jul 14th 2008, 10:35 AM #2

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- Jul 14th 2008, 10:39 AM #3

- Jul 14th 2008, 10:42 AM #4

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- Jul 14th 2008, 10:44 AM #5

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- Jul 14th 2008, 10:50 AM #6

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- Jul 14th 2008, 02:19 PM #7
The "E" is used by the calculator when answers are really small. This is the calculator's way of using scientific notation. 2.789002368E-5 is the same thing as , as Chop Suey had mentioned. In decimal form, this would be the equivalent of

If you were interpret this value [in terms of the likeliness of an event], this would be a very unlikely thing that would occur [I'm saying this with a little knowledge about probabilty...I'm no expert. However, I think I said this correctly].

I hope this clarify things.

--Chris

EDIT: In percent form, this would be .002789002368%.

- Jul 14th 2008, 04:57 PM #8

- Jul 14th 2008, 06:27 PM #9

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