Applied Economics & Statistics 1: An Introduction to Statistics, Measurement, and Presentation of Data* Flashcards
Explain why Statistics is important
- Statistics is not just used in economics.
- Required for many business subjects, social sciences, and hard
sciences. - Needed to process and analyse data, and data available increases
constantly. - Google tracks internet usage, supermarkets purchases, police crime
data… - Statistical techniques required to make sense of the data and enable
personal, business, and scientific decision making.
What’s a ‘statistic’?
A statistic is a number used to communicate a piece of information
The inflation rate is 5.2%.
The average mark on a module is 60%.
The price of a new Toyota Supra is £50,545.
What’s the name for ‘a number used to communicate a piece of information’?
A statistic
Define ‘statistics’
The science of collecting, organizing, presenting, analysing, and interpreting data to assist in making more effective decisions.
- How does this year’s rate of inflation compare with last year’s? Is
there a trend of increasing or decreasing inflation? Is there a
relationship between inflation and interest rates?
- How does the module mark vary compared to previous years, and
other modules? Does changing the lecturer teaching the module
affect average marks?
- The price of a new Toyota Supra is £50,545. The Mazda MX-5 is
cheaper, costing £25,825. What are the differences in the cars’ specs,
and how are they related to price? What other information would you
need for a purchase decision
What are the different types of statistics?
Descriptive and Inferential Statistics
What’s ‘Descriptive Statistics’?
- Methods of organizing, summarizing, and presenting data in an
informative way - Organize and summarize data with graphs and tables.
- Statistical measures describe the characteristics of a distribution
What’s the name for ‘methods of organizing, summarizing, and presenting data in an
informative way’?
Descriptive Statistics
Define ‘Inferential Statistics’
The methods used to estimate a property of a population on the basis of a
sample
What’s the name for ‘the methods used to estimate a property of a population on the basis of a
sample’?
Inferential Statistics
Define ‘population’ in statistics
The entire set of individuals / objects of interest or measurements
obtained from all individuals / objects of interest
Define ‘sample’ in statistics
A portion, or part, of the population of interest
Describe & explain the types of statistical variables
- Qualitative variable - The characteristic being studied is non-numeric. E.g.: gender, religion, eye
colour - Quantitative variable - The characteristic is numerical and the numbers have a meaning. E.g.
number of children in a family, hourly wage, minutes remaining in the
lecture.. It can be further divided into:
1. Discrete - These can assume only certain discrete values. There are usually “gaps” in
between the values. E.g. children in a family —this variable can only take
on a discrete set of values, 0, 1, 2, 3 etc.
2. Continuous - These can assume any value within a range and can be measured to any
required degree of precision. E.g.: weights, heights and time. The time it
takes for each student to finish an exam can be measured anywhere along
the real positive line, i.e. from 0 to infinity and could be measured to the
millisecond.
What are the levels of measurement?
Why are they different?
- Data can be further classified into 4 levels of measurement:
1. Nominal data.
2. Ordinal data.
3. Interval data.
4. Ratio data.
Each require different methods for summarizing and presenting, and a
different type of statistical analysis.
Describe & explain ‘nominal data’
- Nominal Data - Data represented as labels
or names. They have no order. They can only be classified and counted.
E.g., hair colour, religion, sexual orientation, gender. - No other mathematical operations permitted.
E.g., even if we assign numerical values like heterosexual=1, gay=2,
bisexual=3, it makes no sense to say 1+2=3, therefore
heterosexual+gay=bisexual. - Labels are mutually exclusive, e.g., can’t be both Christian and Muslim.
- Labels are exhaustive: every individual observation must belong to a
category (even if it’s ‘Other!’)
What’s the name for ‘data recorded at the nominal level of measurement represented as labels
or names; they have no order; they can only be classified and counted’?
Nominal Data