WHAT IS STATISTIC?

WHAT IS STATISTIC?

1. Statistics is the science of collecting, organizing, presenting, analyzing, and interpreting data to assist in making more effective decisions.

2. 2 types of statistics

   • Descriptive statistics
     • procedures used to organized and summarize data.
   • inferential statistics
     • taking a sample from a population and making estimates about a population based on the sample results.

3. POPULATION

   • Is an entire set of individual or objects of interest or the measurements obtained from all individuals or objects of interest.

4. SAMPLE

   • Is a part of the population.

5. 2 type of variables

   • QUALITATIVE
     • Nonnumeric
       • Interested in the number or percent of the observations in each category.
       • usually summarized in graphs and bar charts.
   • QUATITATIVE
     • NUMERICALLY
       • DISCREATE VARIABLES
         • can assume only certain values, and there are usually gaps
     • CONTINOUS VARIABLE
       • can assume any value within a specified range.

6. LEVEL MEASUREMENT

   • 1. NOMINAL LEVEL
     • A data are sorted into categories with no particular order to the categories.
   • 2. ORDINAL LEVEL
     • Presumes that one classication is ranked higher than another.
   • 3. INTERVAL LEVEL
     • Has the ranking characteristic of the ordinal level of measurement plus. between values is a constant size.
   • 4. RATIO LEVEL
     • All the characteristics of the interval level, plus there is a 0 point and ratio of two values is meaningful.