A 0.1350-g rock sample of unknown concentration was dissolved in hcl and diluted to 100.0 ml. aliquots of 10.00 ml of this unknown solution were added to different volumes of a 2.08 μg/ml ca standard

A 0.1350-g rock sample of unknown concentration was dissolved in hcl and diluted to 100.0 ml. aliquots of 10.00 ml of this unknown solution were added to different volumes of a 2.08 μg/ml ca standard solution and diluted to 200.0 ml. find the weight percent of ca in the rock sample and the associated uncertainty from the x-intercept using the method of least squares.