Particulate matter in the atmosphere follows a legnormal distribytion, In a log-normal distribution \%68.2 of particle diameters fall within RB/ and DRsB. 3elow you see a lognormal distribution, a) What is the geometric mean diameter ( DPB) for this particle sample? b) 68.2% of the particles' diameters lie between two red lines. Based on this what is the geometric standard deviation g of thic log-normal particle size distribution