The following results were obtained when each of a series of standard silver solutions was analyzed by flame-atomic absorption spectrometry: Concentration (ng-mL¹) Absorbance (r.u.) 0 5 10 15 20 25 30 40 0.003 0.127 0.251 0.390 0.498 0.625 0.763 0.771 Determine the slope and intercept of the calibration plot, along with their confidence limits (95%). Using the data from exercise 1 above, estimate the confidence limits for the silver concentration in: a) A sample giving an absorbance of 0.456 in a single determination. b) A sample giving absorbance values of 0.308, 0.317, 0.347, and 0.412 in four separate determinations.