Mean
μ = (Σxᵢ) / n
The mean is the average of the dataset,
calculated by summing all values and
dividing by the total number of values.
Median
Middle value when sorted
The median is the middle number in a
sorted dataset. If the dataset has an
even number of values, it's the average
of the two middle values.
Mode
Most frequent value
The mode is the value that appears most
frequently in the dataset.
Variance
σ² = Σ(xᵢ - μ)² / n
Variance measures how spread out the
data is from the mean. It is the average
of the squared differences from the
mean.
Standard Deviation
σ = √σ²
The standard deviation is the square
root of the variance. It gives a measure
of the spread of the data in the same
units as the data itself.
Range
Range = Max - Min
The range is the difference between the
highest and lowest values in the
dataset.
Quartiles
Q1, Q2 (Median), Q3
Quartiles divide the data into four
equal parts. Q1 is the median of the
lower half, Q2 is the overall median,
and Q3 is the median of the upper half.