nWhat is probability?
A number expressing the likelihood that a specific event will occur,
expressed as the ratio of the number of actual occurrences to the number of
possible occurrences.
What is a set?
A collection of distinct elements having specific common properties: a
set of positive integers.
What is the mean?
A quantity having an intermediate value between several others, from
which it is derived, and of which it expresses the resultant value; usually,
unless otherwise specified, it is the simple average, formed by adding the
quantities together and dividing by their number, which is called an
arithmetical mean. A geometrical mean is the square root of the product of the
quantities.
What is standard deviation?
A statistic used as a measure of the dispersion or variation in a
distribution, equal to the square root of the arithmetic mean of the squares of
the deviations from the arithmetic mean.
Variables:
In algebra, a variable is used to represent a number in a given set of
numbers.
x = {1, 7, 23}
x can only be 1, 7 or 23.
Random Variables :
In statistics, a variable is called a random variable since its value is
determined by chance. Capital letters indicate random variables, lower case the
actual value.
X = x
Discrete vs. Continuous
In the dice example, X is discrete. It can only be a finite (countable)
number of values.
In the CS majors example, X is continuous. It can be any number of values
in its range.
