Discuss te below:
I am conducting research on microscopic toolmark analysis. If I have a toolmark with 27 striations (lines) of varying spatial relationships (orientations), widths and densities, do I use the combination formula to determine the probablity that another toolmark will by chance have a group of at least eight consecutively matching striations: that is the striae have the same spatial relationship, the same density(shades of gray), and the same width. I have done this calculation with the combination formula to determine the probability of having 8 striae out of 27 from one toolmark matching another set of 8 striae out of 27 in a second toolmark in spatial relationship only.