Statistical Concepts and Market Returns Flashcards
Nominal Scale
Data is put into categories that have no particular order
Ordinal Scale
Data is put into categories that can be ordered with respect to some characteristic
Interval Scale
Differences in data values are meaningful, but ratios, such as twice as much or twice as large, are not meaningful
Ratio Scale
Ratios of values, such as twice as much or half as large, are meaningful and zero represents the complete absence of the characteristic being measured
Parameter
Any measurable characteristic of a population
Sample Statistic
Can describe characteristic of a sample
Relative Frequency
Percentage of total observations falling within a frequency
Cumulative Relative Frequency
for an interval is the sum of the relative frequencies for all values less than or equal to that interval’s maximum value
Histogram
Bar chart of data the has been grouped into a frequency distribution
Frequency Polygon
Plots the midpoint of each interval on the horizontal axis and the absolute frequency for that interval on the vertical axis and connects midpoints with straight lines
Quantile
general term for a value at or below which a stated proportion of the data in a distribution lies
Range
Difference between the largest and smallest values in a data set
Variance
Mean of squared deviations form the arithmetic mean or from the expected value of a distribution
Standard Deviation
Positive square root of the variance and is frequently used as a quantitative measure of risk
Chebyshev’s Inequality
States that the proportion of observations within k standard deviations of the mean is 1 - 1/(k^2) for all k > 1. It states that:
36% of observations lie within +/- 1.25 std. dev. of mean
56% of observations lie within +/- 1.5 std. dev. of mean
75% of observations lie within +/- 2 std. dev. of mean
89% of observations lie within +/- 3 std. dev. of mean
94% of observations lie within +/- 4 std. dev. of mean