I am not sure what the proper arrangement of these conformations are from least to most stable. My thinking was this...(but I got the wrong answer). First, I thought that because 2 and 4 are in eclipsed conformations they are least stable. From there I thought that 4 was less stable than 2 because of the steric interactions of the methyl groups. Then of the two staggered conformations 1 and 3, it appears to me that 1 has more steric interaction of the methyl groups than 3. So my ordering from least to most stable was 4,2,1,3. Is there an error in my line of reasoning?