When Variables Are Normally Distributed, About 95% of Observations Lie

question 10

True/False

When variables are normally distributed, about 95% of observations lie ±5 standard deviations from the mean.

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Definitions:

Pooled Variance

A method used in statistical analysis to estimate the variance of two or more different populations by pooling their variances, assuming they have the same variance.

Sample Sizes

The number of observations or units chosen from a larger population for the purpose of statistical analysis.

Weighted Average

An average resulting from the multiplication of each component by a factor reflecting its importance.

Z-score

A numerical metric indicating how a particular value compares to the average of a dataset, expressed by the number of standard deviations it lies from the mean.