Poisson Distribution - on a standard calculator

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March 8th 2011, 10:21 AM
jickjoker

Poisson Distribution - on a standard calculator

hello , can Poisson Distribution problems be worked out on a standard
calculator ?
here is a question ive been trying to solve

If there are 150 typographical errors randomly distributed in a
600-page manuscript, find the probability that any given page has exactly 2 errors.

the solution (2.7183) - 0.25 * (0.25)2 / 2!
the answer given is 0:024

my problem is this part (2.7183) - 0.25
can it be done on a standard calculator ?
if so how?

i apologize for being Old Fashioned
but i like my standard calculator! (Worried)
March 8th 2011, 01:41 PM
mr fantastic

Quote:

Originally Posted by jickjoker

hello , can Poisson Distribution problems be worked out on a standard
calculator ?
here is a question ive been trying to solve

If there are 150 typographical errors randomly distributed in a
600-page manuscript, find the probability that any given page has exactly 2 errors.

the solution (2.7183) - 0.25 * (0.25)2 / 2!
the answer given is 0:024

my problem is this part (2.7183) - 0.25
can it be done on a standard calculator ?
if so how?

i apologize for being Old Fashioned
but i like my standard calculator! (Worried)

Every calculator (including yours) can do the basic opertions of addition, subtraction, multiplication and division. Without wanting to sound facetious, how you do it is that you press the correct buttons in the correct order. It will most likely include using appropriate brackets.

Any problem doing this will be at the user interface, not the calculator. I suggest you ask someone in the flesh to help you if you can't do it.
March 8th 2011, 04:18 PM
awkward

Quote:

Originally Posted by jickjoker

hello , can Poisson Distribution problems be worked out on a standard
calculator ?
here is a question ive been trying to solve

If there are 150 typographical errors randomly distributed in a
600-page manuscript, find the probability that any given page has exactly 2 errors.

the solution (2.7183) - 0.25 * (0.25)2 / 2!
the answer given is 0:024

my problem is this part (2.7183) - 0.25
can it be done on a standard calculator ?
if so how?

i apologize for being Old Fashioned
but i like my standard calculator! (Worried)

The answer should be

$\displaystyle \frac{(0.25)^2}{2!} e^{-0.25}$

It's difficult to compute
$\displaystyle e^{-0.25}$
on a four-function calculator (if that's what you have). So for problems like this you probably want a calculator with an
$\displaystyle e^x$
key, or an
$\displaystyle x^y$
key.