Hi,
The answer is c. The sample is biased.
This is because the sample is taken on a single state, an Rebecca reports a statistic about the nation. Her data contains information only of her state. If she lives in a very cold state, there is probably more homeowners using electric heat than in a hot state.
Just add the two equations.
8x-3y=22
I hope this helps :)
The answer is 13.5*3600=48600/1000cause you already have your meters per second. 13.5m/a and there are 3600 seconds in an hour then you divide that by the meters 1000 and you get **48.6**