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"

class: 0-< 5 5-< 10 10-< 15 15-< 20
rel fraq: .177 .166 .175 .136

class: 20-< 30 30-< 40 40-< 60 60-< 90
rel fraq: .194 .078 .044 .030

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

b) what proportion of the sampled angles are at least 30 degrees?

c) roughly what proportion of angles are between 10 degrees and 25 degrees?

d) construct a histogram and comment on any interesting features.