Ten Different Families Were Tested for the Average Number of Gallons

Ten different families were tested for the average number of gallons of water they used per day before and after viewing a conservation video. A $90 \%$ confidence interval for the difference of the means after and before the training, $\mu _ { A } - \mu _ { B }$ was determined to be $( - 10.8 , - 4.2 )$ .

A) We know that $90 \%$ of families will use between $4.2$ and $10.8$ fewer gallons of water each day after viewing the conservation video.
B) Based on this sample, we are $90 \%$ confident that the average decrease in daily water consumption after viewing the conservation video is between $4.2$ and $10.8$ gallons.
C) We are $90 \%$ confident that a randomly selected family who has viewed the video will use between $4.2$ and $10.8$ more gallons of water per day compared to a randomly selected family who has not viewed the video.
D) Based on this sample, we are $90 \%$ confident that the average increase in daily water consumption after viewing the conservation video is between $4.2$ and $10.8$ gallons.
E) We are $90 \%$ confident that a randomly selected family who has viewed the video will use between $4.2$ and $10.8$ fewer gallons of water per day compared to a randomly selected family who has not viewed the video.

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