Flashcards: Introduction to Statistics and Sampling — 38 cartões

What is Statistics?

The study of how to collect, organize, analyze, and interpret data.

What is the first step in a statistical investigation cycle?

Posing a question.

What step follows collecting data in a statistical investigation?

Analyzing the data.

What is the final step in a statistical investigation cycle?

Interpreting the results.

What limits the accuracy of a statistical procedure?

The accuracy of the data or facts it is based on.

What is an individual in a statistical study?

A person or object included in the study.

What does a population consist of in statistics?

Every individual of interest in the study.

What does a sample consist of in statistics?

Only some of the individuals of interest in the study.

Where do population data come from?

From every individual of interest.

Where do sample data come from?

From only some individuals of interest.

What is a variable in data analysis?

A characteristic of an individual that is measured or observed.

What defines a quantitative variable?

It has numerical values allowing operations like addition or averaging.

How does a qualitative variable classify individuals?

By placing them into categories or groups.

Which variables are quantitative in a Mount Everest summit study?

Height, weight, and age.

Which variables are qualitative in a Mount Everest summit study?

Gender and nationality.

What is a population parameter?

A numerical measure describing an aspect of a population.

What does a sample statistic describe?

An aspect of a sample using a numerical measure.

How does a population parameter differ from sample statistics?

A population parameter is fixed, but sample statistics vary between samples.

In the Mount Everest example, what is the number of left-handed climbers?

A population parameter.

In the Mount Everest example, what is the number of right-handed climbers in a sample?

A sample statistic.

What characterizes the nominal level of measurement?

It consists of names, labels, or categories with no implied ordering.

What type of data does the ordinal level consist of?

Data that can be arranged in order but with undetermined or meaningless differences.

What distinguishes the interval level of measurement?

Ordered data with meaningful differences but zero is just a position on the scale.

What defines the ratio level of measurement?

Ordered data with meaningful differences and ratios and a true zero.

What is the rule for categorizing a variable's level of measurement?

It should be categorized at the highest level appropriate for its data.

What does descriptive statistics organize and summarize?

Information from samples or populations.

What is the main purpose of inferential statistics?

To draw conclusions about the population from a sample.

What defines a simple random sample?

Every sample and individual have an equal chance of selection.

What is the first step to draw a simple random sample?

Number all population members sequentially.

Why doesn't a random sample guarantee population representation?

It can overrepresent one group by chance.

How do you select 30 cars from 500 using random sampling?

Assign numbers 1 to 500 and use a random-number generator.

What is a simulation in statistics?

A numerical or mathematical imitation of a real-world phenomenon.

What happens to selected numbers in sampling with replacement?

They remain in the population and can be selected again.

How does stratified sampling divide the population?

Into characteristic-based strata for random sampling.

How does cluster sampling select samples?

By randomly selecting clusters and including all their members.

How does systematic sampling select population members?

By choosing every kth member after a random start.

What defines multistage sampling?

Using several methods to create smaller groups ending in cluster samples.

What is convenience sampling?

Sampling from population members who are readily available.