1. The results from a sediment particle sieve analysis from a sediment sample taken from the River Taff are given below in Table 1. i) Plot the sediment particle distribution curve and classify the sediment according to its size; ii) plot a histogram to show the distribution of the sediment particle size intervals and iii) calculate the arithmetic mean grain size (dmean) and comment on how this compares to the median particle size (d50). The arithmetic mean grain size is given by: dmean=inmiindimi where mi is the percentage mass retained on a sieve of size di. Table 1 River bed sediment taken from the River Taff