(Sec 1.2) The number of contaminating particles on a silicon wafer prior to a certain rinsing process was determined for each wafer in a sample of size 100, resulting in the following frequencies: number of particles 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 frequency 1 2 3 12 11 15 18 10 12 4 5 3 1 2 1 (a) What proportion of the sampled wafers had at least one particle