Data

A study is done in which the data collected are the number of cars a person has owned in his or her lifetime. This is an example of qualitative data. (T/F)

False - Data is quantitative

Sampling Distributions

Distributions of sample statistics such as means and proportions

What are the names given to values that describe samples (1) and values that describe populations (2)?

1. Statistics 2. Parameters

Random Variable

A numerical outcome of an experiement or random phenomenon

What is a random variable?

A numerical outcome of an experiment or random phenomenon

Survey

A random study, generally in the form of an interview or questionnaire, that provides researchers with information about a certain population

Probability Distributions

A way of matching outcomes with their probabilities of success

Which of the following are examples of qualitative data? (A) The airline on which a person chooses to book a flight (B) The average number of women in chapters of Gamma Goo sorority (C) The race/ethnicity of survey respondents (D) The closing Dow Jones average on 50 consecutive market days (E) The number of people earning each possible grade on a statistics test (F) The scores on a given exam

A, C, E, F (if letter grades were given)

Descriptive Statistics (Exploratory Data Analysis)

Analytic or graphic data

Continuous Data

Can be measured or take on values in an interval (quantitative) - ex. time of day

Qualitative Data (Categorical Data)

Data that can be classified into a group

Discrete Data

Data that can be listed or placed in order (quantitative) - ex. number of heads in 20 coin flips

Quantitative Data

Data that can be measured or identified on a numerical scale

Which of the following are discrete and which are continuous? (A) The number of jelly beans in a jar (B) The ages of a group of students (C) The humidity in Atlanta (D) The number of ways to select a committee of three from a group of ten (E) The number of people who watched the Super Bowl in 2002 (F) The lengths of fish caught on a sport fishing trip

Discrete: A, D, E Continuous: B, C, F

Control Group

Group that receives no stimuli in an experiment

Treatment Group

Group that receives the stimuli in an experiment

Why do we need to take care with data collection?

In order to avoid bias

Why do we need to sample?

It is usually too difficult or too expensive to survey every member of the population

Which of the following are statistics an which are parameters? (A) The proportion of all voters who will vote Democrat in the next election (B) The proportion of voters in a Gallup Poll who say they will vote Democrat in the next election (C) The mean score of the home team in all NFL games in 2005 (D) The proportion of Asian students among all students attending high school in the state of California (E) The mean difference score between a randomly selected class taught statistics by a new method and another class taught by an old method (F) The speed of a car

Statistics: B, E, F Parameters: A, C, D

A study is done in which the data collected are the number of cars a person has owned in his or her lifetime. This is an example of discrete data. (T/F)

True - Data is countable

Experiment Observational Study

Used to determine the reactions of persons or things to certain stimuli

Inferential Statistics

Using data from samples to make inferences about the population from which the sample was drawn

Parameters

Values that describe a population

Statistics

Values that describe a sample