Answer :

For this we first need to know how much watt hours are used in 12 house which we can find by taking 960/2=480 now we just need to take 960*4=3840 and add 480 which gives us are end answer of 4320 watt hours. Enjoy!=)
The answer would be 4,320 watts because 960*4.5=4,320. (The 4.5 came from the amount of days because 12 hours is 1/2 one day)