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.
Statisticians use summary measures to describe the amount of variability or spread in a set of data. The most common measures of variability are the range, the interquartile range (IQR), variance, and standard deviation. View Video Lesson The Range. The range is the difference between the largest and smallest values in a set of values. For example, consider the following numbers: 1, 3, 4, 5, 5, 6, 7, 11. For this set of numbers, the range would be 11 - 1 or 10. The Interquartile Range (IQR) The interquartile range (IQR) is a measure of variability, based on dividing a data set into quartiles. Quartiles divide a rank-ordered data set into four equal parts. The values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively. 1  Q1 is the middle value in the first half of the rank-ordered data set. 2  Q2 is the median value in the set. 3  Q3 is the middle value in the second half of the rank-ordered data set.