Measures of Location and Dispersion Flashcards
Quantile (fractile) is…
a value at or below which a stated fraction of the data is situated.
Interquartile range (IQR) is…and is calculated as…
the difference between the third and first quartiles of a dataset.
IQR = Q3 − Q1
Formula for finding the percentile is…
L y (percentile) = (n + 1)(y/100)
What is dispersion?
The variability of a population or central around the central tendency.
What is absolute dispersion?
The amount of variability present without comparison to any reference point or benchmark.
Measures of absolute dispersion include:
1)Range
2)Mean Absolute Deviation (MAD)
3)Variance
4)Standard Deviation
The range is?
A difference between the minimum and maximum values within the dataset.
The mean absolute deviation (MAD) for a sample formula is:
MAD = Summation of (Deviations Xi - Xbar) / n
Sample variance can be defined as?
The expected value (the probability-weighted average) of squared deviations from a random variable’s expected value.
The Sample Variance formula is:
S2 = Summation of (variable - sample mean)^2 / n - 1
Standard Deviation can be defined as?
The positive square root of the variance: a measure of dispersion in the same units as the original data.
Standard Deviation can be fined by?
S = Squared root of Sample Variance
Sample standard deviation can help us to understand…?
The gap between the arithmetic mean and the geometric mean.
The relation between the arithmetic mean (Xbar) and geometric mean (Xbar sub-G) is calculated as:
Xbar (sub-G) ≈ Xbar - s^2 / 2
Downside risk is defined as?
Risk of incurring return below a specified value.