e280 chapter 1 1.1 1.2

refers to the summary of important aspects of a data set. this includes collecting data, organizing the data , and then presenting the data in the forms of charts or tables

refers to drawing conclusions about a large set of data called a population  based on a smaller set of sample data. a population is defined as all members of a specified group (not necessarily ppl) whereas a sample is a subset of that particular population

• Cross sectional data- refers to data collected by recording a characteristic of many subjects at the same point in time, or without regard to differences in time.
• Time series data- refers to data collected by recording a characteristic of a subject over several time periods. Time series can include daily, monthly, quarterly, or annual observations.

consists of all items of interest in a statical problem

is a subset of the population.

• example, the population of letters
• in the alphabet would be the collection of all 26 letters.  Randomly selecting a subset of letters would
• create a sample

the certain aspect of a population (such as the average age or the percentage who said yes to a question), that measurement is called

statistic

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