Poly(3-hydroxybutyrate) (PHB), a semicrystalline polymer that is fully biodegradable and biocompatible, is obtained from renewable resources. From a sustainability perspective, PHB offers many attractive properties though it is more expensive to produce than standard plastics. The accompanying data on melting point (°C) for each of 12 specimens of the polymer using a differential scanning calorimeter appeared in an article.

180.5 181.7 180.9 181.6 182.6 181.6
181.3 182.1 182.1 180.3 181.7 180.5

Compute the following:
(a) The sample range.
(b) The sample variance S2 from the definition (Hint: First subtract 180 from each observation.)
(c) The sample standard deviation.
(d) S2 using the shortcut method.