The standard value for a healthy human's body temperature is 37°C, to the nearest Celsius degree, although this value is only an approximation. In fact, the temperature of a healthy person varies by as much as 1.5°C each day, being lowest in the morning and peaking in the evening. On North American fever thermometers, a "normal" body temperature is usually indicated as 98.6°F. (a) Explain how this "normal" value in the Fahrenheit system is obtained from the "normal" value in the Celsius system. (b) Explain why stating the value for a "normal" human temperature with three significant digits, as 98.6°F, is misleading. (c) What would be a better "normal" value in the Fahrenheit system?