Chapter 2 Probability and Statistics
2.1 Displaying Distributions with Graphs
1. Rates: A rate is a more general measure in which one quantity is divided
by another quantity, where both quantities don't necessarily need to have
the same unit of measure. It can be equal to any value, including negative
numbers. Like proportions, and it can be expressed as a number or a
percentage.
2. Distribution:In probability theory and statistics, a probability distribution is
the mathematical function that gives the probabilities of occurrence of
possible outcomes for an experiment. It is a mathematical description of a
random phenomenon in terms of its sample space and the probabilities of
events.
3. Roundoff errors:Round-off error is the kind of inaccuracy we get by taking
a certain number of decimal places instead of taking the entire number.
4. Bar graph:Bar graphs are the pictorial representation of data (generally
grouped), in the form of vertical or horizontal rectangular bars, where the
length of bars are proportional to the measure of data. They are also
known as bar charts. Bar graphs are one of the means of data handling in
statistics.
5. Dotplot:A dot plot is a simple form of data visualization that consists of
data points plotted as dots on a graph with an x- and y-axis. These types
of charts are used to graphically depict certain data trends or groupings.
, Common mistakes:
➔ Uneven sized dots
➔
➔ Un even vertical spacing
➔ Slanted Verticals
Always look for:
Patterns: (center((Average = the mean or the median)), shapes (peaks and
skewness) spread → the range)
Outliers or deviations (anything that sticks out to you that is different)
6. Outliers:An outlier is an observation that lies an abnormal distance from
other values in a random sample from a population. In a sense, this
definition leaves it up to the analyst (or a consensus process) to decide
what will be considered abnormal.
2.1 Displaying Distributions with Graphs
1. Rates: A rate is a more general measure in which one quantity is divided
by another quantity, where both quantities don't necessarily need to have
the same unit of measure. It can be equal to any value, including negative
numbers. Like proportions, and it can be expressed as a number or a
percentage.
2. Distribution:In probability theory and statistics, a probability distribution is
the mathematical function that gives the probabilities of occurrence of
possible outcomes for an experiment. It is a mathematical description of a
random phenomenon in terms of its sample space and the probabilities of
events.
3. Roundoff errors:Round-off error is the kind of inaccuracy we get by taking
a certain number of decimal places instead of taking the entire number.
4. Bar graph:Bar graphs are the pictorial representation of data (generally
grouped), in the form of vertical or horizontal rectangular bars, where the
length of bars are proportional to the measure of data. They are also
known as bar charts. Bar graphs are one of the means of data handling in
statistics.
5. Dotplot:A dot plot is a simple form of data visualization that consists of
data points plotted as dots on a graph with an x- and y-axis. These types
of charts are used to graphically depict certain data trends or groupings.
, Common mistakes:
➔ Uneven sized dots
➔
➔ Un even vertical spacing
➔ Slanted Verticals
Always look for:
Patterns: (center((Average = the mean or the median)), shapes (peaks and
skewness) spread → the range)
Outliers or deviations (anything that sticks out to you that is different)
6. Outliers:An outlier is an observation that lies an abnormal distance from
other values in a random sample from a population. In a sense, this
definition leaves it up to the analyst (or a consensus process) to decide
what will be considered abnormal.
