During the winter months, the temperatures at the Starneses’ Colorado cabin can stay well below freezing (32°F or 0°C ) for weeks at a time. To prevent the pipes from freezing, Mrs. Starnes sets the thermostat at 50°F. The manufacturer claims that the thermostat allows variation in home temperature of σ = 3°F. Mrs. Starnes suspects that the manufacturer is overstating the consistency of the thermostat.