The Easiest Guide For Statistics Formulas

Yusif Morsy
3 min readOct 23, 2020

Sample Mean

The average of a set of data. used to calculate the central tendency, standard deviation and the variance of a data set.

just stands for the sample mean. Σ is The summation. xi all of the x-values. n is the number of observations in the sample.

Population Mean

μ just stands for the sample mean. Σ is The summation. N is the number of observations in the population.

Sample Variance

s2 Sample variance. xi value of the one observation. Mean of data. n The number of observations.

Population Variance

σ2 population Variance. μ just stands for the sample mean. Σ is The summation. N is the number of observations in the population.

Population Standard Deviation

σ population Standard deviation. μ just stands for the sample mean. Σ is The summation. N is the number of observations in the population.

Sample Standard Deviation

sx Sample Standard deviation. just stands for the sample mean. Σ is The summation. xi all of the x-values. n-1 is the number of observations in the sample.

Coefficient Sample Variation

The coefficient of variation, divide the standard deviation by the mean and multiply by 100.

CV coefficient of variation. S standard deviation . mean .

Coefficient Population Variation

The coefficient of variation, divide the standard deviation by the mean and multiply by 100.

CV coefficient of variation. σ population Standard deviation. μ just stands for the sample mean.

Sample Covariance

xi data value of x. yi data value of y. mean of x. ȳ mean of y. N-1 number of data values.

Population Covariance

xi data value of x. yi data value of y. mean of x. ȳ mean of y. N number of data values.

Sample Correlation Coefficient

Population Correlation Coefficient

The variance of a sample for grouped data

f frequency of the class. m midpoint of the class

The variance of a population for grouped data

Z-Score

T-Distribution Formula

See you next Article.

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