 # Summary Statistics The Art and Science of Learning from Data : Third Edition : Alan Agresti & Christine Franklin

ISBN-10 1784483516 ISBN-13 9781784483517
323 Flashcards & Notes
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Remember faster, study better. Scientifically proven. • ## 1 statistics: the art and science of learning from data

• what is descriptive statistics?
summarizing and analyzing the data, thats obtained.
• what is inferencial statistics?
making decisions and predictions based on the data for answering statistical questions.
• what is a (sample) statistic?
a numerical summary of a sample taken from the population.
• ## 2 Exploring data with graphs and numerical statistics

• when is a variable categorial and when is it quantitative?
it's categorial if the observations can be put in categories, and its's quantitative if the observations can be expressed in numbers.
• what is the key characteristic of a quantitive variable?
there has to be different magnitudes, or you need to be able to take an average of the variable.
• when is a quantitive variable dicrete, and when is it continuous?
it is descrete when it's possible values form a set of seperate numbers, it's continuous when the possible values form an interval.
• what is the modal category?
the category with the highest frequency.
• what is the pareto principle?
a small subset of categories often contains most of the observations.
• what is a histogram?
a bar graph that shows the (relative) frequencies of the observations of a quantative variable.
• if the set of data is small which type of graph is usually preferred?
the stem-and-leaf plot or the dot plot is usually preferred.