The endocrine component of the pancreas consists of islet cells (islets of Langerhans) that create and release important hormones directly into the bloodstream. Two of the main pancreatic hormones are insulin, which acts to lower blood sugar, and glucagon, which acts to raise blood sugar.
Variability is a measure of the spread of a data set. Learn more about the different measures of variability including the range, variance, and standard deviation, and how they are used in the field of Psychology.
Interpretation according to the definition of direct variation: When the radius (the independent variable) is doubled, the circumference (the dependent variable) is also doubled. This is how the relationship of the variables C (circumference) and r (radius) is described in direct variation. I hope that you realize that it's not just y=kx. If you know the key phrases and the definition (and the relationship), you can solve real-life situation problem involving direct variation.