The equation used to predict how long a cold will last is y=-1.8 + 0.09x1 + 3.2x2 - 1.9x3, where x1 is person's temperature on the first day, x2 is number of people seen each day, and x3 is the amount of sleep the person gets. Use this equation to predict how long a cold will last with a temperature of 100.4 degrees, an average of 6 people seen each day, and 4 hours of sleep.