The measurement problem is an important open question for the interpretation of the foundations of quantum mechanics. For the purpose of solving this problem, we focus from a new angle on the interpretation of the superpositionprinciple that is the origin of the measurement problem. As a result, we show that the measurement problem at issuecannot arise, provided the mathematical and physical aspects of the superposition principle are considered correctly.Our work demonstrates that since any mathematical superposition of eigenstates is never a new eigenstate, the superposed state at issue, if any, should be interpreted simply as a statistical ensemble of possible states that occursequentially, instead of a mixed state indicative of simultaneous occurrence. Actually, this view leads to the conclusion that the concept of the currently accepted state vector and the motivation of the measurement problem have noperfect ground from both mathematical and physical aspects. Furthermore, using mainly mathematical method ratherthan thought experiments, we offer a realistic interpretation of the superposition of eigenstates based on ensemble ofquantum states, thereby helping to capture the essence of the measurement problem which actually is not implicatedin Apparatus and Observer.