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Q
uantitative
R
easoning &
P
roblem
S
olving
128
© 2014 Pacific Crest
W
hat Do You Already Know?
Tapping into your existing knowledge
1. What are five things you know will happen (your certainty of them happening is 100% )?
2. What are five situations where outcomes can differ because of random behavior?
3. What is the probability of each of the following? (Make your own prediction and then find statistical
data online and see how close you were.)
event
My Prediction
(1 in ___ chance)
Statistical
Probability
rolling a 3 with a single die
living until you are 60 in the U.S.
getting hit by a meteorite
getting into a car accident in the next year
being in a plane crash
winning mega-millions
getting cancer
M
athematical Language
Terms and notation
act of God
— a very rare event outside the control of anyone
probability distribution
— a function of a discrete random variable yielding the probability that the
variable will have a given value
randomness
—
lack of pattern or predictability in events; randomness may be both perceived or real
random error
—
the inconsistent inaccuracies of observed or measured values in science
random variable
—
is a variable whose values are the outcomes of a statistical experiment
statistical regularity
—
consistency of repeated outcomes so the sample takes on the behavior of the
population distribution as the sample size increases
variable
—
a quantity that can take on different value(s) and is represented by a letter or symbol
variation
— the amount of spread in a set of numbers
I
nformation
What you need to know
R
eadings
R
esources