Chapter 1 What is Statistics

Ratio

Meaningful 0 Interpretation

What is descriptive statistics?

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

A marketing class of 50 students evaluated the instructor using the following scale: superior, good, average, poor, and inferior. The descriptive summary showed thefollowing survey results: 2% superior, 8% good, 45% average, 45% poor, and 0%inferior.

Most students rated the instructor as poor or average.

quaLITative variable

Object or individual

What is a population?

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

Interval

distance between values is meaningful -"units are known"

Discrete data

referring to Counting "gaps"

ordinal

relative ranking based on defined attributes

What is statistics?

science of collecting, organizing, presenting, analyzing, and interpreting data

QuanTITative variable

variable reported numerically

What is a Sample?

A portion or part of the population of interest

If Gallup, Harris, and other pollsters asked people to indicate their political party affiliation as Democrat, Republican, or Independent, the data gathered would be an example of which scale of measurement?

C) Nominal

nomial

Lables and names, no order -Lowest level of measurement

What level of measurement is the Centigrade temperature scale?

Attribute

What type of variable is "pounds of popcorn" served at a movie theater?

Continuous

What type of variable is the number of auto accidents reported in a given month?

Discrete

A listing of 100 family annual incomes is an example of statistics.

False

Descriptive statistics are used to find out something about a population based on a sample.

False

Which word is NOT part of the definition of descriptive statistics?

Predicting

What type of variable is the number of robberies reported in your city?

Quantitative

The incomes of 50 loan applicants are obtained. Which level of measurement is income?

Ratio

The general process of gathering, organizing, summarizing, analyzing, and interpreting data is called ________.

Statistics

The main purpose of descriptive statistics is to:

Summarize data in a useful and informative manner.

What is inferential statistics?

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

Which of the following is an example of a continuous variable?

Tons of concrete to complete a parking garage

A sample is a portion or part of the population of interest.

True

To infer something about a population, we usually take a sample from the population.

True

Continuous dats

measuring something