Chapter 1
What is statistics?
statistics is the science of organizing and summarizing numerical or non-numerical information. Facts or data, either numerical or non-numerical, are collected, organized, and summarized to provide useful and accessible information about a particular subject.
what is a frequency distribution?
A frequency distribution is the organization of raw data in table form, using classes and frequencies.
whats the mean?
the average
whats a probability experiment?
A probability experiment is a chance process that leads to well-defined results called outcomes.
whats a outlier
An outlier is an extremely high or an extremely low data value when compared with the rest of the data values.
what is a census?
When data are collected from every subject in the population
what's a histogram?
The histogram is a graph that displays the data by using contiguous vertical bars (unless the frequency of a class is 0) of various heights to represent the frequencies of the classes.
whats the median?
The median is the midpoint of the data array. The symbol for the median is MD.
whats a outcome
An outcome is the result of a single trial of a probability experiment.
whats a event
An event consists of a set of outcomes of a probability experiment.
whats cluster sampling?
A cluster sample is obtained by dividing the population into sections or clusters and then selecting one or more clusters and using all members in the cluster(s) as the members of the sample.
The frequency polygon is a graph that displays the data by using lines that connect points plotted for the frequencies at the midpoints of the classes. The frequencies are represented by the heights of the points.
whats the mode?
The value that occurs most often in a data set is called the mode.
whats a sample space
A sample space is the set of all possible outcomes of a probability experiment.
whats a equally likely event
Equally likely events are events that have the same probability of occurring.
What's a non sampling error?
A non sampling error occurs when the data are obtained erroneously or the sample is biased, i.e., nonrepresentative.
whats a ogive
The ogive is a graph that represents the cumulative frequencies for the classes in a frequency distribution.
whats a Z score or a standard score?
A z score or standard score for a value is obtained by subtracting the mean from the value and dividing the result by the standard deviation. The symbol for a standard score is z.
whats a tree diagram
A tree diagram is a device consisting of line segments emanating from a starting point and also from the outcome point. It is used to determine all possible outcomes of a probability experiment.
whats the complement of a event
The complement of an event E is the set of outcomes in the sample space that are not included in the outcomes of event E. The complement of E is denoted by (read “E bar”).
whats a confounding variable
A confounding variable is one that influences the dependent or outcome variable but was not separated from the independent variable.
whats a dot plot
A dotplot is a statistical graph in which each data value is plotted as a point (dot) above the horizontal axis.
whats Chebyshev's theorem?
The proportion of values from a data set that will fall within k standard deviations of the mean will be at least , where k is a number greater than 1 (k is not necessarily an integer).
what does mutually exclusive mean?
Two events are mutually exclusive events or disjoint events if they cannot occur at the same time
whats a box plot
A boxplot is a graph of a data set obtained by drawing a horizontal line from the minimum data value to Q1, drawing a horizontal line from Q3 to the maximum data value, and drawing a box whose vertical sides pass through Q1 and Q3 with a vertical line inside the box passing through the median or Q2.