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36 Cards in this Set
 Front
 Back
Statistic

A descriptive measure of a sample
(A numerical measure describing a characteristic of a sample) 

Descriptive statistics

Method of organizing, summarizing, and presenting data


Population

The group of all items of interest


Statistical Inference

The process of making an estimate, prediction, or decision about a population based on sample data


Sample

A set of data drawn from the population


One form of statistics uses numerical techniques to summarize data. To obtain information on whether the data are closely clustered or widely scattered around the "typical" data value, a measure of ___________ is computed.

variability


Nominal Variable

Categorical values


Ordinal Variables

Categorical values, but order has meaning


Interval Variables

Numerical Values. Difference between two values has meaning.


Positively Skewed

The tail of the graph extends farther to the right. Therefore, the relative frequency distribution of the values is positively skewed.


Negatively Skewed

The tail of the graph extends farther to the left. Therefore, the relative frequency distribution of the values is negatively skewed.


Population Data

Data collected from every item of interest


Sample Data

Those collected from only some of the items of interest


Parameter

Numerical measure describing a characteristic of a population


A frequency distribution can be structured either as a table or as a graph, but in either case the distribution presents the same to elements...

1. A record of the frequency (the number of individuals in each category).
2. The set of categories that make up the original measurement scale. 

Mode

A measure of location, defined as the observation that occurs with greatest frequency


Outlier

An unusually small or large observation


Range

A measure of variability, defined as the largest observation minus the smallest observation


Sample statistic

A numerical value used as a summary measure for a sample


Skewness

A measure of the shape of a data distribution


Median

A measure of central location provided by the observation in the middle when the data are arranged in ascending order


A measure of variability provided by the difference between the first and third quartiles

Interquartile Range


A measure of central location computed by summing the observations and dividing the sum by the number of observations.
(average) 
Mean


Standard deviation

Population Standard deviation s= square root of S squared


Simple Event

One specific outcome of a random experiment


Random Experiment

An action or process that results in one of several welldefined outcomes


Event

A collection of one or more outcomes of a random experiment


Sample Space

The collection of all outcomes of a random experiment


The intersection of events A and B

The event containing the simple events belonging to both events A and B


Mutually Exclusive Events

Events that have no simple events in common


The union of events A and B

The event containing all the simple events belonging to Event A, Event B, or both


The complement of Event A

The event that consists of all simple events that are not in Event A


If two events A and B are mutually exclusive, then they are _________________

not independent


The National Road Freight Survey, operated by the European Union, divides commercial vehicles into three groups based on their weights 25 tons, 510 tons, and over 10 tons. A simple random sample is taken from each group and data are collected on each vehicle in the sample. Which sampling method is this?

Stratified Random Sampling


In a study of bank loans to small business, a random sample of banks is selected. For the banks in the sample, data are collected on every small business loan provided by that particular month. Which sampling method is this?

Cluster Sampling


A lawn firm surveys a sample of its customers on their satisfaction levels with the firm. Clients are numbered sequentially, and Excel is used to randomly select 100 numbers assigned to the clients. The sample is obtained by using the clients whose numbers correspond to the 100 randomly selected numbers. Which sampling method is this?

Simple Random Sampling
