Thursday, April 2, 2015

What is geometric probability? Please compare it to binomial distribution and provide an everyday example.Satistics - having trouble...

Geometric probability refers to the probability of an area
rather than a number.  Geometric probability compares the size of the favorable area to
the total area.  It is usually written as a fraction, however it can also be given as a
decimal or percent.


Suppose a rectangular pool is
surrounded by a deck and a fence.  The pool is 30 ft long and 15 ft wide.  The deck is a
consistent width around the pool.  If a baseball is hit into the fenced area, what is
the probability that the baseball will land in the
pool?


Allow x to represent the width of the
deck.


The favorable area is the area of the pool.  30 * 15
= 450 sq ft


The total area is the area of the pool plus the
additional area of the deck.


total length as a binomial: 
30 + x + x = 2x + 30


total width as a binomial:  15 + x + x
= 2x + 15


total area:  (2x + 30)(2x + 15) = 4x^2 + 90x +
450


The geometric probability of the ball landing in the
pool is:


450 / (4x^2 + 90x +
450)


If you know the width of the deck, you can get a
numerical answer.  For example, if the deck is 6 ft
wide...


450 / (4 * 6^2 + 90 * 6 +
450)


450 / 1134 `~~` 0.3968 or about
40%.


I hope this helped.

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