# Re-expression units conversion

I was arguing with my Stats teacher today in class because we were stuck on the topic of re-expression. She decided to give me extra credit if I could prove to her, using the internet, something related to unit conversions during re-expression. When you perform a power transformation with a power of $-1/2$ or $-1$, you're supposed to change the units and the value to negative (ie. for a power of $-1$ you might get $-32.8$ -gallon/mile). Are you supposed to change it back to $32.8$ gallon/mile?

• When you say "When you perform -1/2 and -1 degree of re-expression", what are you talking about? Are you trying to discuss power transformations? Box-Cox transformations? Something else? – Glen_b Nov 27 '12 at 7:33
• When you do y^-1/2 or y^-1 – user17211 Nov 29 '12 at 0:29
• so yes power transformations – user17211 Nov 29 '12 at 0:29