Question

In a population of a beetle species, you notice that there is a 3 : 1 ratio of shiny to dull wing covers. does this ratio prove that the shiny allele is dominant? (assume that the two states are caused by two alleles of one gene.) if not, what does it prove? how would you elucidate the situation?

Answer 1

No, it the ratio does not prove that the shiny wing is dominant. The ratio only says that shiny wing is more common than the dull wings. 
To know which allele is dominant, you need to do an experiment by crossing various beetle and observe the ratio of the offspring phenotype.