Electric Bill

Recently, my wife blamed me for the elelctric bill. :(
According to her, we got about 1000 yen higher electric bill compared to the same month last year.

Actually, last month I kept my PentiumD 930 box powered on during the week end days.
We can guess that consumes roughly 130W/hour, and that means I consumed 130W/h x 24h x 2 days x 4 weeks = 25Kwh more electric power. But, when my wife blamed me, I made a mistake in the above calculation. I estimated that lower than actual by 1 digit, 2.5-5kwh. :(

Yes, mom. You're right.... :o