Marjorie, Alexei, and Niva all take the same anthropology final exam. The professor announces, "The mean for the exam was 65% and the standard deviation was 10%. That standard deviation is too small so I will use z-score scaling so that the standard deviation becomes 15%. I will not be adjusting the mean."

After scaling, Marjorie's grade stays the same but Alexei's grade goes down, and Niva's grade goes up. Using course concepts, explain how this is possible.