The grade you earn in math varies inversely with the number of minutes per night you watch television. A person who watches 90 minutes of TV per night will earn a 60% in their mai class. Round to the nearest minute The resistance R of an electrical wire varies directly with the length of the wire L and inversely with the cross-sectional area of the wire A. An electrical wire with a cross-sectional area of 4 square centimeters has a resistance of 1.25 ohms when its length is 10 cm. The constant of variation k = Variation Model: Find the resistance of the same type of wire with a cross-sectional area of 9 square centimeters and a length of 72 centimeters