Certain chemotherapy dosages depend on a patient's surface area. According to the Gehan and George model, 5 = 0.02235h0'42246w0'51455, where h is the patient's height in centimeters. w is his or her weight in kilograms, and S is the approximation to his or her surface area in square meters. Joanne is 180 cm tall and weighs 90 kg. Use a differential to estimate how much her surface area changes after her weight decreases by 3 kg. Joanna's surface area changes by approximately [:l (Round to ve decimal places as needed.)