I will give branliest if you can answer all these questions

Good guys i hope you will me about this question,, plase

Russell's study compared gpa of those students who volunteered for academic study skills training and those who did not elect to take the training. he found that those who had the training also had higher gpa. with which validity threat should russell be most concerned?

You would like to compare your firm's cost structure to that of your competitors. however, your competitors are much larger in size than your firm. which one of these would best enable you to compare costs across your industry? common-size income statement. pro forma balance sheet. statement of cash flows. common-size balance sheet