Business Analytics Ch. 1

What are the three resons to study statistics?

(1) data are collected everywhere and require statistical knowledge to make the information useful, (2) statistical techniques are used to make professional and personal decisions, and (3) no matter what your career, you will need a knowledge of statistics to understand the world and to be conversant in your career.

SAMPLE

A portion, or part, of the population of interest.

nominal level of measurement

Data recorded at the nominal level of measurement is represented as labels or names. They have no order. They can only be classified and counted.

ordinal level of measurement

Data recorded at the ordinal level of measurement is based on a relative ranking or rating of items based on a defined attribute or qualitative variable. Variables based on this level of measurement are only ranked or counted.

ratio level of measurement

Data recorded at the ratio level of measurement are based on a scale with a known unit of measurement and a meaningful interpretation of zero on the scale

interval level of measurement

For data recorded at the interval level of measurement, the interval or the distance between values is meaningful. The interval level of measurement is based on a scale with a known unit of measurement.

DESCRIPTIVE STATISTICS

Methods of organizing, summarizing, and presenting data in an informative way.

POPULATION

The entire set of individuals or objects of interest or the measurements obtained from all individuals or objects of interest.

INFERENTIAL STATISTICS

The methods used to estimate a property of a population on the basis of a sample

Statistics

The science of collecting, organizing, presenting, analyzing, and interpreting data to assist in making more effective decisions

qualitative variable

a categorical variable for which each value represents a discrete category

quantitative variable

takes numerical values for which arithmetic operations such as adding and averaging make sense