conversations.from: human
conversations.value: Darla needs to pay $4/watt of electricity for 300 watts of electricity, plus a $150 late fee. How much does she pay in total?
conversations.from: assistant
conversations.value: First find the total cost of the electricity: $4/watt * 300 watts = $1200
  Then add the late fee: $1200 + $150 = $1350