A student designs an experiment to determine the solubility product constant, \(K_{sp}\), of calcium sulfate, \(\text{CaSO}_4(s)\). The student adds an initial mass of \(1.500\text{ g}\) of pure \(\text{CaSO}_4(s)\) to \(250.0\text{ mL}\) of distilled water and stirs the mixture at \(25^\circ\text{C}\) until equilibrium is established. The mixture is then filtered through pre-weighed filter paper to collect the undissolved \(\text{CaSO}_4(s)\).

During the filtration, the student washes the precipitate on the filter paper with several portions of room-temperature distilled water instead of a chilled solution containing a common ion. The collected solid is dried to constant mass and weighed. The student calculates the molar solubility and \(K_{sp}\) using the relationship:
\[ \text{Mass of dissolved }\text{CaSO}_4 = \text{initial mass} - \text{mass of dry recovered solid} \]
Which of the following correctly predicts the error in the calculated value of \(K_{sp}\) and provides the correct justification?