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...

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 the article
“The Melting Behaviour of Poly(3-Hydroxybutyrate)
by DSC. Reproducibility Study” (Polymer Testing,
2013: 215–220).
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