answer all questions with explanation

Problem 1.4: Getting experience with higher moments of the log-normal distribution: The powder that has to be analyzed consists of orthorhombic salt crystals with an aspect ratio of 1/2/4. The density p of the crystal is 2500 kg/m3. A sample of 750 g is analyzed by sieving and the following residues were measured (similar to Problem 1.2): Mesh size/ um 0 45 63 90 125 180 250 355 500 710 1000 1400 Residue / g 1.1 1.9 5.25 7.5 21.8 37.5 37.5 97.0 90.0 112.5 285.0 52.5 a) What kind of distribution is shown in the table? Plot the fraction and the cumulative fraction versus the particle diameter. b) Can the distribution be described by a lognormal distribution? Name and calculate the two parameters needed to determine a lognormal distribution