Define Statistics. A statistics is the science of collecting, organizing, summarizing, and analyzing information to draw conclusions or answer questions. In addition, statistics is about providing a measure of confidence in any conclusions.
An individual is a person or object that is a member of the population being studied.
A statistic is a numerical summary of a sample.
In Problems 7–14, determine whether the underlined value is a parameter or a statistic.
State Government Following the 2010 national midterm election, 18% of the governors of the 50 United States were female: Parameter
Illegal Drugs In a national survey of 1300 high school students (grades 9 to 12), 32% of respondents reported that someone had bullied them at school: Statistic
Batting Average Ty Cobb is one of major league baseball’s greatest hitters of all time, with a career batting average of 0.366: Parameter
Hygiene Habits A study of 6076 adults in public rest rooms (in Atlanta, Chicago, New York City, and San Francisco) found that 23% did not wash their hands before exiting: Statistic
Problems 15–22, classify the variable as qualitative or quantitative.
Nation of origin: Qualitative
Grams of carbohydrates in a doughnut: Quantitative
Number of unpopped kernels in a bag of ACT microwave popcorn: Quantitative
Phone number: Qualitative
In Problems 23–30, determine whether the quantitative variable is discrete or continuous.
Goals scored in a season by a soccer player: Discrete
Length (in minutes) of a country song: Continuous
Temperature on a randomly selected day in Memphis, Tennessee: Continuous
Points scored in an NCAA basketball game: Discrete
In Problems 31–38, determine the level of measurement of each variable.
Nation of origin: Nominal
Volume of water used by a household in a day: Ratio
Highest degree conferred (high school, bachelor’s, and soon) Ordinal
Assessed value of a house : Ratio
In Problems 39–44, a research objective is presented. For each, identify the population and sample in the study.
The Gallup Organization contacts (1028 teenagers: Population) who are (13 to 17 years of age: Sample) and live in the United States and asks whether or not they had been prescribed medications for any mental disorders, such as depression or anxiety.
In Problems 9–16, determine whether the study depicts an observational study or an experiment.
Seventh-grade students are randomly divided into two groups. One group is taught math using traditional techniques; the other is taught math using a reform method. After 1 year, each group is given an achievement test to compare proficiency: Experiment
A survey is conducted asking 400 people, “Do you prefer Coke or Pepsi?” Observational Study