In this article, we investigate how a rational agent forms their opinion based on prior knowledge, available information, and the opinions of other agents. We propose methodology of how to purposefully merge agent’s opinion and expert opinions. We describe the agent’s opinion and the opinions of experts in the form of distributions. Formulating opinion formation as a decision-making task and solve it using Fully Probabilistic Design (FPD). To demonstrate our approach, we apply the solution on simulated data describing features of mobile phone brands. Methodology is verified on a test bed example of choosing a mobile phone brand based on expert opinions while taking into account agent’s trust in experts.