Find the [Ca²⁺] in ppm in the unknown (Sample II, each of the three) using the calibration equation.

calibration equation = y = (341.2 ±30.45)x +(278 ±201.9)

Calculate the weight percent of Ca2+in the unknown samples and the associated uncertainty from the calibration equation. The associated uncertainty should be determined based on the uncertainties in the slope and intercept. Show your calculations (note: the uncertainties in the concentration of the standards should not be considered).