Variability is a measure of how much each score in a group of scores differs from the what?

Variability is a measure of how much each score in a group of scores differs from the mean value.

What are variance, mean and standard deviation?

Variance measures how far each number is from the mean value. While the mean value is the average of all given numbers in the table.

Standard deviation measures the data on how dispersed the numbers are in relation to the mean. If data is closed to the mean it means lower the standard deviation and higher the standard deviation means how far data is from the mean.

Therefore variance is the distance from the mean.

Learn more about Variance, Mean and Standard deviation here.

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The holy roman empire.

Ghana, first of the great medieval trading empires of western africa (fl. 7th–13th century). it was situated between the sahara and the headwaters of the sénégal and niger rivers, in an area that now comprises southeastern mauritania and part of mali.