Problem 4. The turbidity of samples will be measured in a nelson turbidimeter. The instrument should be calibrated with standard formazine solution, 1mg/L of which is equal to 1 NTU unit. The Nephelometer measures the dispersion of light as light intensity (I) (W/cm2). The dispersed light intensities of several diluted samples of standard formazine solution are measured in the Nephelometer and values are tabulated as follows: a) Using the Table above, generate the calibration curve along with the linear equation and R2 values. Do you think that the calibration curve is acceptable? (14p) b) A sample from Kepez Wastewater Treatment influent is diluted 5 times, and subsequently the light dispersion intensity of the diluted sample is measured as 0.152W/cm2 in the nephelometer. Accordingly, what is the turbidity of Kepez Wastewater Treatment effluent in NTU unit. (6p)