26. Automated electron backscattered diffraction is now being used in the study of fracture phenomena. The following information on misorientation angle (degrees) was extracted from the article “Observations on the Faceted Initiation Site in the Dwell-Fatigue Tested Ti-6242 Alloy: Crystallographic Orientation and Size Effects (Metallurgical and Materials Trans., 2006: 1507–1518).

Class: 0–5 5–10 10–15 15–20 Rel freq: .177 .166 .175 .136 Class: 20–30 30–40 40–60 60–90 Rel freq: .194 .078 .044 .030

a. Is it true that more than 50% of the sampled angles are smaller than 15 , as asserted in the paper?

b. What proportion of the sampled angles are at least 30 ?

c. Roughly what proportion of angles are between 10 and 25 ?

d. Construct a histogram and comment on any interesting features.