Comparing variability

Hi guys, I am having a difficulty understanding the question itself. So from what I understand it's asking me to compare the variability by which I assume it means std dev. Now I think the 2 mm is the population std dev. So if s1 and s2 are the sample std devs then I need to calculate P(s1-s2>0). This is what I got so far and am not sure if my understanding is correct. Can anyone help me out figuring out this question? Thanks.