A student wishes to establish experimentally the number of fungal particles in a fixed volume of air. He uses a liquid medium suitable for the growth of most fungi and exposes the liquid to air in a rectangular container of dimensions 15 cm × 15 cm, he then seals the container. He then measures the depth of air above the liquid inside the sealed container and finds it to be 10 cm. After a period of 1 week there are 9 patches of fungus growing on the liquid medium. Calculate the number of fungal particles present in 1 m3 in the original air sample and express your answer in scientific notation, to one significant figure. Type your answer in to the box below; the correct units are already given. Number of fungal particles in 1 m3 of air = Superscript (↑) fungal particles m-3