Elementary Statistics

Elementary Statistics

1. A parameter is a numerical measurement describing some characteristic of a population

   • statistic is a numerical measurement describing some characteristic of a sample.

2. Quantitative (or numerical) data consist of numbers representing counts or measurements.

   • Categorical (or qualitative or attribute) data consist of names or labels that are not numbers representing counts or measurements.
     • Discrete data result when the number of possible values is either a finite number or a “countable” number.
       • Continuous (numerical) data result from infinitely many possible values that correspond to some continuous scale that covers a range of values without gaps, interruptions, or jumps
         • The nominal level of measurement is characterized by data that consist of names, labels, or categories only.
           • the ordinal level of measurement if they can be arranged in some order, but differences (obtained by subtraction) between data values either cannot be determined or are meaningless.
             • interval level of measurement is like the ordinal level, with the additional property that the difference between any two data values is meaningful.
               • The ratio level of measurement is the interval level with the additional property that there is also a natural zero starting point