Download Area For this course, area is the number of square units needed to

Area
For this course, area is the number of square units needed to fill up
a region on a flat surface. In later courses, the idea will be
extended to cones, spheres, and more complex surfaces. Also
see surface area.
Compound Event
A compound event in probability is an outcome that depends on
two or more other events. For example, finding the probability
that both a red ball and also a blue block are drawn from a bag in
two draws.
Desired Outcome
In the context of probability, “successful” usually means a desired
or specified outcome (event), such as rolling a 2 on a number cube
(probability of
).
Equivalent Fractions
Two fractions are equivalent if they have the same numerical
value. For example, 3/6 and 5/10 are equivalent fractions.
Experimental Probability
The probability based on data collected in experiments. The
experimental probability of an event is defined to
be
.
Lowest Common Denominator
The smallest common multiple of the denominators of two or more
fractions. For example, the LCD of
and
is 24.
Interval
A set of numbers between two given numbers.
Mean
The mean, or average, of several numbers is one way of defining
the “middle” of the numbers. To find the average of a group of
numbers, add the numbers together then divide by the number of
numbers in the set. For example, the average of the numbers 1, 5,
and 6 is (1 + 5 + 6) ÷ 3 = 4. The mean is generally the best
measure of central tendency when there are not outliers in the data
set. See average.
Measure of Central Tendency
Mean, median, and mode are all measures of central tendency,
reflecting special statistical information about a set of data. See
center of a data distribution.
Median
The middle number of an ordered set of data. If there is no distinct
middle, then the average of the two middle numbers is the
median. The median is generally more accurate than the mean as a
measure of central tendency when there are outliers in the data set.
Multiplicative Identity
The multiplicative identity property states that multiplying any
expression by 1 leaves the expression unchanged. That is, a(1)
= a. For example, 437 x · 1 = 437x.
Outcome
Possible result in an experiment or consequence of an action.
Outlier
A number in a set of data that is much larger or much smaller than
the other numbers in the set.
Parallelogram
A quadrilateral with two pairs of parallel sides.
Percent
(%) A ratio that compares a number to 100. Percents are often
written using the “%” symbol. For example, 0.75 is equal
to
or 75%.
Perimeter
The distance around a figure on a flat surface.
Possible Outcomes
In the context of probability, outcomes with any chance of
happening.
Probability
A number that represents how likely an event is to happen. When
a event has a finite number of equally-likely outcomes, the
probability that one of those outcomes, called A, will occur is
expressed as a ratio and written as:
. For example, when
flipping a coin, the probability of getting tails, P(tails), is 1/2
because there is only one tail (successful outcome) out of the two
possible equally likely outcomes (a head and a tail). Probability
may be written as a ratio, decimal, or percent. A probability of 0
(or 0%) indicates that the occurrence of that outcome is
impossible, while a probability of 1 (or 100%) indicates that the
event must occur. Events that “might happen” will have values
somewhere between 0 and 1 (or between 0% and 100%).
Proportional Relationship
Two values are in a proportional relationship if a proportion may
be set up that relates the values.
Rectangle
A quadrilateral with four right angles.
Repeating Decimals
A repeating decimal is a decimal that repeats the same sequence of
digits forever from some point onward. For example,
4.56073073073… is a decimal for which the three digits 073
continue to repeat forever. Repeating decimals are always the
decimal expansions of rational numbers.
Sample Space
The collection of all possible outcomes of an event.
Scaling
(scale) The ratio between a length of the representation (such as a
map, model, or diagram) and the corresponding length of the actual
object. For example, the map of a city may use one inch to
represent one mile.
Terminating Decimal
A terminating decimal is a decimal that has only a finite number of
non-zero digits, such as 4.067. Terminating decimals are a
particular kind of repeating decimal for which the repeating
portion is zeros, so the example could be written 4.0670000000…
but it is not necessary to write the zeros at the end.
Theoretical Probability
A calculated probability based on the possible outcomes when
each outcome has the same chance of occurring: (number of
successful outcomes)/(total number of possible outcomes).
Trapezoid
A quadrilateral with at least one pair of parallel sides.
Triangle
A polygon with three sides.