Formulae for the standard deviation. Whilst it is not necessary to learn the formula for calculating the standard deviation, there may be times when you wish to include it in a report or dissertation. The standard deviation of an entire population is known as Ï (sigma) and is calculated using:
After 8-20 hours, the egg hatches and the fly enters the maggot stage. It begins to feed on whatever the egg was laid on, usually decomposing flesh. The maggot gorges itself with food until it is ready to enter the pupal stage, at which point the maggot travels away from the food source to a moist spot.
If food is available, flies can multiply quickly. Their primary food sources are food waste, organic garbage and feces. A single fly can lay around 9,000 eggs during its life. Fly eggs hatch within 24 hours to produce maggots, the first stage in their development. If maggots survive the first 14 to 36 hours, they transform into pupae and thereafter into fully grown flies.