statics chapter 1 Flashcards
What is the plural sense definition of statistics?
An aggregate or collection of numerical facts.
What is the singular sense definition of statistics?
The science of collecting, organizing, presenting, analyzing and interpreting numerical data for the purpose of assisting in making a more effective decision.
What are the two main areas of statistics?
- Descriptive Statistics
- Inferential Statistics
What does Descriptive Statistics focus on?
Summary calculations, graphs, charts and tables.
What is Inferential Statistics used for?
To generalize from a sample to a population.
What is the first stage in any statistical investigation?
Collection of data.
Name three common methods for data collection.
- Telephone survey
- Mailed questionnaire
- Personal interview
What is the second stage in statistical investigation?
Organization of data.
What is the purpose of the presentation of data?
To reorganize, classify, compile, and summarize data to present it in a meaningful form.
What does the analysis of data involve?
Extracting relevant information from the summarized data through elementary mathematical operations.
What is the final stage in statistical investigation?
Inference of data.
Define Statistical Population.
The collection of all possible observations of a specified characteristic of interest and being under study.
What is a Sample?
A subset of the population, selected using some sampling technique to represent the population.
What is Sampling?
The process or method of sample selection from the population.
What does Sample size refer to?
The number of elements or observations to be included in the sample.
What is a Census?
Complete enumeration or observation of the elements of the population.
Define Parameter in statistics.
Characteristic or measure obtained from a population.
What is a Statistic?
Characteristic or measure obtained from a sample.
What is a Variable?
An item of interest that can take on many different numerical values.
What are Qualitative Variables?
Qualitative Variables are nonnumeric variables that can’t be measured.
Examples include gender, religious affiliation, and state of birth.
What are Quantitative Variables?
Quantitative Variables are numerical variables that can be measured.
Examples include balance in checking account and number of children in family.
What are the two types of Quantitative Variables?
Quantitative variables are either discrete or continuous.
Discrete variables can assume only certain values (e.g., number of bedrooms), while continuous variables can assume any value within a specific range (e.g., air pressure in a tire).
What are some applications of statistics?
Statistics is applicable in almost all fields of human endeavor and daily life.
Examples include invention of drugs and extent of environmental pollution.
What are the main uses of statistics?
Statistics enlarges our knowledge of complex phenomena.
Uses include presenting facts, data reduction, measuring variations, comparison techniques, estimating population characteristics, hypothesis testing, studying relationships, and forecasting.
What are some limitations of statistics?
Statistics has limitations such as dealing only with quantitative information and aggregates of facts.
It can be misused and should be used by experts.
What is the importance of measurement scales in statistics?
Proper knowledge of measurement scales is essential for applying the correct statistical methods.
Measurement scale refers to the value assigned to data based on order, distance, and fixed zero.
What is the property of Order in measurement?
The property of order exists when an object with more of an attribute is assigned a bigger number.
This must hold for all objects in the real world.
What is the property of Distance in measurement?
The property of distance concerns the relationship of differences between objects.
Equal differences between numbers reflect equal differences in the real world.
What is Fixed Zero in measurement?
A measurement system possesses a fixed zero if an object with none of the attribute is assigned the number zero.
This is necessary for meaningful ratios between numbers.
What are the four levels of measurement scales?
The four levels of measurement scales are nominal, ordinal, interval, and ratio.
Each possesses different properties of measurement systems.
What are Nominal Scales?
Nominal scales classify data into mutually exclusive categories without order or ranking.
Examples include political party preference, sex, marital status, country code, and regional differentiation.
What are Ordinal Scales?
Measurement systems that possess the property of order but not the property of distance.
Differences between the ranks do not exist and arithmetic operations are not applicable.
What is a key characteristic of Ordinal Scales?
Ordering is the sole property.
Examples include letter grades and rating scales.
Give an example of an Ordinal Scale.
Letter grades (A, B, C, D, F).
Also includes rating scales like Excellent, Very good, Good, Fair, Poor.
What are Interval Scales?
Measurement systems that possess the properties of order and distance, but not the property of fixed zero.
Ratios are meaningless due to the lack of a meaningful zero.
What arithmetic operations are applicable to Interval Scales?
All except division and multiplication.
Relational operations are also possible.
Give an example of an Interval Scale.
IQ.
Temperature in Fahrenheit is another example.
What are Ratio Scales?
Measurement systems that possess all three properties: order, distance, and fixed zero.
True ratios exist between different units of measure.
What is a defining feature of Ratio Scales?
The presence of a true zero allows for meaningful ratios.
Example: Bekele’s height to Martha’s height ratio.
What arithmetic operations are applicable to Ratio Scales?
All arithmetic and relational operations.
This includes addition, subtraction, multiplication, and division.
Give an example of a Ratio Scale.
Weight.
Other examples include height, number of students, and age.
What type of scale is your checking account number?
Nominal Scale.
It serves as a name for your account.
What type of scale is your checking account balance?
Ratio Scale.
It measures the amount of money you have.
What type of scale is the order of elimination in a spelling bee?
Ordinal Scale.
It serves as a measure of your spelling ability.
What type of scale is your score on the first statistics test?
Interval Scale.
It measures your knowledge of statistics.
What type of scale is your score on an individual intelligence test?
Interval Scale.
It measures your intelligence.
What type of scale is the distance around your forehead?
Ratio Scale.
It measures an actual length.
What type of scale is the response to the statement ‘Abortion is a woman’s right’?
Ordinal Scale.
Responses range from ‘Strongly Disagree’ to ‘Strongly Agree’.
What type of scale are times for swimmers to complete a race?
Ratio Scale.
It measures actual time taken.
What type of scale are months of the year?
Nominal Scale.
They classify time without order or distance.
What type of scale is socioeconomic status classified as low, middle, and upper?
Ordinal Scale.
It indicates a ranking of status.
What type of scale is blood type classified as A, B, AB, and O?
Nominal Scale.
It categorizes individuals without order.
What type of scale are pollen counts provided between 1 and 10?
Ordinal Scale.
The values do not represent actual counts.
What type of scale are regional numbers of Ethiopia?
Nominal Scale.
They serve as identifiers without order.
What type of scale is the number of students in a college?
Ratio Scale.
It measures a count of individuals.
What type of scale is the net wages of a group of workers?
Ratio Scale.
It measures actual monetary amounts.
What type of scale is the height of men in the same town?
Ratio Scale.
It measures actual height.
