Ch. 1

A simple figure is called a __________.

statistic (singular)

Ordinal Level

Data that can be ranked are referred to as ordinal measures. For example, consumer response to the sound of a new speaker might be excellent, very good, fair, or poor. 1. Data classifications are represented by distinct labels or names that have relative values (extra-large, large, medium, small, extra small; gold, silver, bronze; hot, medium, mild). 2. Because of the relative values, the data classified can be ranked.

Types of Quantitative Variables:

Discrete & Continuous

When statisticians analyze sample data in order to draw conclusions about the characteristics of a population, this is referred to as

Statistical inference

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

Statistics

A collection of figures can be called ________________.

Statistics (plural)

The main purpose of descriptive statistics is to

Summarize data in a useful and information manner

Survey

Example: Company surveys about 1200 homes on an ongoing basis to determine which TV program are being watched.

The American Statistical Association

has guidelines that advise statisticians to maintain ethical standards.

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

False

A store asks shoppers for their zip codes to identify market areas. Zip codes are an example of ratio data.

False

Categorizing voters as Democrats, Republicans, and Independents is an example of interval level measurement.

False

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

False

If we select 100 persons from 25,000 registered voters and question them about candidates and issues, the 100 persons are referred to as the population.

False

SAT scores are an example ratio data.

False

The Union of Electrical Workers of America with 9,128 members polled 362 members about a new wage package that will be submitted to management. The population is the 362 members.

False

The order in which runners finish in a race would be an example of continuous data.

False

The ordinal level of measurement is considered the "lowest" level of measurement

False

The terms descriptive statistics and inferential statistics can be used interchangeably.

False

There are four levels of measurement: qualitative, quantitative, discrete, and continuous.

False

Interval Level

If one observation is greater than the another by a certain amount, and the zero point is arbitrary, the measurement is on an interval scale. For example, the difference between temperatures of 70 degrees and 80 degrees in 10 degrees. Likewise, a temperature of 90 degrees is 10 degrees more than a temperature of 80 degrees, and so on.

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

Ratio

The reported unemployment is 5.5% of the population. What level of measurement is used to measure unemployment?

Ratio

Income is a variable often used in business and economics. Income is an example of a variable that uses the

Ratio scale

When pharmaceutical companies try a new vaccine on a portion or part of a population, this is called a

Sample

The length of a bridge, measured in meters, is an example of

Quantitative Data

The names of the positions in a corporation, such as chief operating officer or controller, are examples of what type of variable?

Ordinal

The names of the positions in a corporation, such as chief operating officer or controller, are examples of what type of variable?

Qualitative

Examples of a statistic:

- Home sales declined 6.5% in South Carolina in April, 2006 compared to sales in April, 2005. - Tuition and fees for resident undergraduate students at public four year institutions averaged $5,491 for 2005-06, a 7.1% increase over 2004-05. - Approx. 24 million medicare beneficiaries were enrolled in the new prescription drug program as of January, 2006.

The four levels of measurement:

1. Nominal (lowest/ most primitive level) 2. Ordinal 3. Interval 4. Ratio *pinot NOIR*

Why study statistics?

1. Numerical information is everywhere. 2. Statistical techniques are used to make decision that affect our lives. 3. Knowledge of statistical methods will help you understand why decisions are made and give you a better understanding of how they affect you.

Sample

A portion, or subset, of the population being studied.

Continuous Variable

A quantitative variable that can assume any value within a range Examples: amount of snow for the winter of 2005-2006 in Toronto, the pressure in a tire, or a person's weight. *typically, continuous variables are the result of measuring something. We can measure the pressure in a tire, or the amount of snow in Toronto.

Discrete Variable

A quantitative variable that can only assume certain values. There is a "gap" between the values. Examples: number of children in a family, number of customers in a carpet store in an hour, or number of commercials aired last hour on radio station WNOK. *a family can have 2 or 3 children, but not 2.445. WNOK can air five or six commercials, but not 5.75. *Usually discrete variables result from counting.

Line Chart

A statistical tool designed to describe the movement of a series of numbers over a long period of time (such as production, imports, wages, and stock market trends).

Quantitative Variable

A variable being studied that can be reported numerically. Examples: the balance in your checking account, ages of the members of U.S. Congress, speeds of cars traveling along I-70, number of customers served...

Qualitative Variable

A variable that has the characteristic of being non-numeric. Examples: classification of students at your university by the state of birth, gender, or college affiliation (Liberal Arts, Business, etc.), brand of soft drink, eye color, type of vehicle...

Median

Average

The performance of personal and business investments is measured as a percentage called "return on investment." What type of variable is "return on investment"?

Continuous

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

Continuous

What type of variable is the number of gallons of gasoline pumped by a filling station during a day?

Continuous

Ratio Level

If the distance between numbers is a constant size, there is a true zero point, and the ratio of two values is meaningful, then the data are ratio scale. For example, the distance between $200 and $300 is $100, and in the case of money there is true zero point. If you have zero dollars, there is an absence of money (you have none). Also, the ratio between $200 and $300 is meaningful. 1. Data classifications are ordered according to the amount of the characteristic they possess. 2. Equal differences in the characteristics are represented by equal differences in the numbers assigned to the classifications. 3. The zero point reflects the absence of the characteristic.

What level of measurement is the Centigrade temperature scale?

Interval

Which of the following is true?

No matter what your career, you need a knowledge of statistics to understand the world.

A survey includes a question about marital status that has the following responses: single, married, divorced, separated, or widowed. What is the level of measurement for this question?

Nominal

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

Nominal

Shoe style is an example of what level of measurement?

Nominal

The Equal Employment Opportunity Act requires employers to classify their employees by gender and national origin. Which level of measurement is this?

Nominal

A university wishes to conduct a student survey. In one of the questions, students are asked to mark their gender as either male or female. Gender is an example of the

Nominal scale

What level of measurement is a person's "favorite sport"?

Not Ordinal

The members of each basketball team wear numbers on their jerseys. What scale of measurement are these numbers considered?

Not ordinal

A bank asks customers to evaluate its drive-through service as good, average, or poor. Which level of measurement is this classification?

Ordinal

Nominal Level

The "lowest" level of measurement. If data are classified into categories and the order of those categories is not important, it is the nominal level of measurement. Examples are gender (male, female) and political affiliation (Republican, Democratic, Independent, etc.). If it makes no difference whether male or female is listed first, the data are nominal level. 1. Data categories are represented by labels or names. 2. Even when the labels are numerically coded, the data categories have no logical order.

Population

The collection, or set, of all individuals, objects, or measurements whose properties are being studied. The entire set of individuals or objects of interest of the measurements obtained from all individuals or objects of interest.

Inferential Statistics

The methods used to estimate something about a population, based on a sample.

Statistics

The science of collecting, organizing, presenting, analyzing, and interpreting numerical data for the purpose of making more effective decisions.

Descriptive Variable

The techniques used to describe the important characteristics of a set of data. This includes organizing the data values into a frequency distribution, computing measures of location, and computing measures of dispersion and skewness.

Inferential Level

This facet of statistics deals with estimating a population parameter based on a sample statistic. For example, 2 out of the 10 hand calculators sampled are defective, we might infer that 20 percent of the production is defective. 1. Data classifications are ordered according to the amount of the caracteristic they possess. 2. Equal differences in the characteristic are represented by equal differences in the measurement.

A marketing research agency was hired to test a new smartphone. Consumers rated it outstanding, very good, fair, or poor. The level of measurement for this experiment is ordinal

True

A population is a collection of all individuals, objects, or measurements of interest.

True

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

True

Based on a sample of 3,000 people, the civilian unemployment rate in the United States was 5.5%. The 5.5% is referred to as a statistic.

True

Credit rating scores are an example of interval data.

True

Statistics is defined as a body of techniques used to facilitate the collection, organization, presentation, analysis, and interpretation of information for the purpose of making better decisions.

True

Statistics is used to report the summary results of market surveys.

True

The CIA World Factbook cited these numbers for the United States: The birthrate is 13.66 births per 1,000 of the population, The average life expectancy for females is 81.17 years. Approximately 316.7 million persons reside in the United States. Each of these numbers is referred to as a statistic.

True

The average number of passengers on commercial flights between Chicago and New York City is an example of a statistic.

True

The monthly average number of cases of people testing positive for virus infection, by country, is an example of a statistic.

True

The number of children in a family is a discrete variable.

True

The principal difference between the interval and ratio scale is that the ratio scale has a meaningful zero point.

True

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

True

Which of the following is not an example of a statistic?

a. A list of the profits earned last year for 100 companies in the United States b. The average profit earned last year for the 10 top companies on the Dow Jones Index c. he unemployment rate in the United States for last month d. The weekly income of the typical high school graduate compared to a typical college graduate (wrong answer)

The final rankings of the top 20 NCAA college basketball teams are an example of which level of measurement?

a. Interval (wrong) b. Ordinal c. Ratio d. Nominal

Your height and weight are examples of which level of measurement?

a. Interval (wrong) b. Ratio c. Nominal d. Ordinal

The Nielsen Ratings break down the number of people watching a particular television show by age. What level of measurement is age?

a. Nominal (wrong) b. Ordinal c. Ratio d. Interval

Which one of the following is not an example of discrete data?

a. Number of households watching the Home Shopping Network b. Number of miles between New York City and Chicago (right answer) c. Number of members of the Denver Lions Club d. Number of employees reporting in sick

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

a. Predicting (right answer) b. Summarizing c. Organizing d. Analyzing

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

a. Ratio (wrong) b. Interval c. Continuous d. Discrete

Respondents were asked, "Do you now earn more than or less than you did five years ago?" What is this level of measurement?

a. Ratio (wrong) b. Ordinal c. Nominal d. interval

An example of a qualitative variable is

color of ink in a pen

Descriptive Statistics

methods of organizing, summarizing, and presenting data in an informative way

When TV advertisements report that "2 out of 3 dentists surveyed indicated they would recommend Brand X toothpaste to their patients," an informed consumer may question the conclusion because

the advertisement does not include the total number of dentists surveyed.

Ethical Statisticians

use honesty and integrity when summarizing, analyzing, and interpreting data