Answer:
the second homeowner's annual heating cost is $371.42
Step-by-step explanation:
given data
efficiency = 100 %
annual cost = $2600
coefficient of performance = 7
to find out
the second homeowner's annual heating cost
solution
we know that COP ( coefficient of performance ) is inversely proportional to electricity bill or annual heating cost
so
we can say COP for heat pump 1 is =
=
![(1)/(100%)]()
COP of pump 1 = 1
so

put here value

annual cost = $371.42
so the second homeowner's annual heating cost is $371.42