(R7) Quantitative Methods: Statistical Concepts and Market Returns Flashcards
Population definition
All members of a specified group; all descriptive measures are called parameters
Sample definition
Subset of a population; all descriptive measures are called sample statistics
Definition of Parameter
Any descriptive measure of a population
Definition of Sample statistic
Any descriptive measure of a sample
Inferential statistics
involves making forecasts, estimates, or judgements about a larger group (population) from the smaller group (sample) actually observed
4 Types of measurement scales
- Nominal
- Ordinal
- Interval
- Ratio
These are ordered from weakest to strongest level of measurement
Nominal Measurement Scale
Categorical data that is not ranked; weakest level of measurement
Ordinal Measurement Scale
Ranking system due to some characteristic; but this tells us nothing about the difference between the rankings
Interval Measurement Scale
Provides ranking but also assurance that the difference between scale values are equal; I.e. temperature
Ratio Measurement scale
They have all the characteristics of interval measurement scales as well as a true zero point as the origin; strongest level of measurement
Frequency Distribution
a tabular display of data grouped into intervals; works with all measurement scales
Absolute frequency
Number of observations in each interval
How to construct a frequency distribution
- Sort the data in ascending order
- Calculate the range of the data, defined as range = maximum value - minimum value
- Choose the number of intervals (k)
- Determine the interval width (max - min)/k
Relative frequency
Absolute frequency of each interval divided by the total number of observations
Cumulative relative frequency
Adds up the relative frequencies as we move from the first to the last interval
Histogram definition
Bar chart of data that have been grouped into a frequency distribution
Frequency Polygon
Plot the midpoint of each interval on the x-axis and the absolute frequency on the y-axis; then connect the points with a straight line
Three methods to display data graphically
- Histogram
- Frequency polygon
- Cumulative frequency distribution
Measures of central tendency (Definition and types)
Specifies where the data is centered; Ex: arithmetic mean, median, mode, weighted mean, geometric mean
Arithmetic mean definition
Is the sum of all observations divided by the number of observations (the scribble m notation represents the population mean; the x with the bar on top is the notation for a sample mean); the best estimate of a single period return