Recall the following context from the previous investigation. When building a house, the amount of insulation in the attic impacts the annual heating and cooling costs for the house. In general, the more insulation used the lower the annual heating and cooling costs. The following tables show some specific information for a particular house. Function f # of bags of insulation applied depth of insulation in the attic (inches) 11 2 20 3.6 28 5 36 6.5 40 7.2 50 9 61 11 70 12.6 78 14 Function g depth of insulation in the attic (inches) estimated annual heating/cooling cost (dollars) 15 940 13 1000 11 1100 9 1250 7 1500 6.5 1750 5 1900 4 2750 3 3600 Untried When you see g ( f ( 20 ) ) , what are you supposed to do first in order to determine its value? Evaluate g ( 20 ) . Find the input value that makes g ( x ) = 20 . Find the input value that makes f ( x ) = 20 . Evaluate f ( 20 ) . Does g ( f ( 20 ) ) have a real-world meaning in this context (even if you can't find the value in the tables)? Yes. No. If you answered "yes" in part (b), select its meaning. (If you answered "no", select "I answered no in part (b)".) It is the depth of attic insulation (in inches) when 20 bags of insulation are used. It is the estimated annual heating/cooling costs (in dollars) when the insulation depth is 20 inches. It is the estimated annual heating/cooling costs (in dollars) when 20 bags of insultation are used to insulate the attic. It is the number of bags of insultation needed to pr