Sleep related groaning, also called catathrenia, causes you to groan vocally while you sleep. Sleep related groaning is a long-lasting disorder that often occurs nightly. The groaning sound is usually quite loud. Your breathing becomes unusually slow during a groaning episode. You take in a slow, deep breath.
The Gini coefficient (or Gini ratio) is a summary statistic of the Lorenz curve and a measure of inequality in a population.he Gini coefficient (or Gini ratio) is a summary statistic of the Lorenz curve and a measure of inequality in a population.
Pearson's Correlation Coefficient. Correlation is a technique for investigating the relationship between two quantitative, continuous variables, for example, age and blood pressure. Pearson's correlation coefficient (r) is a measure of the strength of the association between the two variables.earson's Correlation Coefficient. Correlation is a technique for investigating the relationship between two quantitative, continuous variables, for example, age and blood pressure. Pearson's correlation coefficient (r) is a measure of the strength of the association between the two variables.