We carried out the ?XRF? analysis and sequential extraction of soils contaminated with lead using lead nitrate of known amount. Noting pertinently, that the nominal lead concentration obtained in the contaminated soil sample earlier in the experimental work is 2,415 mg/kg after appropriate procedures. Looking at our results, we found that the concentration of the solid contaminated samples: OL S 1-2, and OL S 3-2 (2,080.26, and 2,080.41 mg/kg) respectively in that order are very close to the concentration of lead also obtained using the ?XRF? analysis for the liquid solutions obtained from the sequential extraction procedures of soil samples: ?OL S 1-2, and 3-2 as (2,110 mg/kg, and 2,090 mg/kg) respectively in that order. It would not be necessary to carry out the long ?sequential extraction procedure in determining the lead concentration in contaminated soil as the ?XRF? analysis result can be relied on based on the closeness of the results obtained from the two different procedures. Most pertinently and interestingly, the results of the ?XRF and sequential extraction have been predicted numerically and randomly generated based on the ?Monte Carlo simulation technique. The predicted and numerically generated results are good estimates of the experimental results.