Card Set Information
Stats Stat Statistics
Chapter 1: Introduction
It is a field of study concerned with summerizing and interpreting data, then making decisions based on that data.
A quantity calculated in a sample to estimate a value in a population.
The branch of statistics concerned with drawing conclusions about a population from a
sampling, followed bysample. This is generally done through random inferences made
about central tendency, or any of a number of other aspects of a distribution.
The median is a popular measure of central
tendency. It is
the 50th percentile of a distribution.
To find the median of a number
of values, first order them, then find the observation in the middle
: the median
of 5, 2, 7, 9, and 4 is 5. (Note that if there is an even number of values,
one takes the average of the middle two
: the median of 4, 6, 8, and 10 is 7.)
The median is often more appropriate than the mean in skewed distributions, or in situations with outliers.
R = P/100 x (N + 1)
R - Rank
P - Desired Percentile (known)
N - Number on list being ranked