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| Question 345529:  For a certain hot-water heater, the increase in heating expenses is directly proportional to  increase in water-temperature setting. If heating expenses increase by $24 when the water-temperature setting is increased by 20 degrees Fahrenheit, by how much will heating expenses increase when the water-temperature setting is increased by 15 degrees Fahrenheit?
 A. $16  B. $18  C. $19  D. $20  E. $21
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! For a certain hot-water heater, the increase in heating expenses is directly proportional to increase in water-temperature setting. ---
 E = kt
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 If heating expenses increase by $24 when the water-temperature setting is increased by 20 degrees Fahrenheit,
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 Find "k":
 24 = k*20
 k = 6/5
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 Equation:
 E = (6/5)t
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 by how much will heating expenses increase when the water-temperature setting is increased by 15 degrees Fahrenheit?
 E(15) = (6/5)15
 E = 18
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 Cheers,
 Stan H.
 
 A. $16 B. $18 C. $19 D. $20 E. $21
 
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