In the face of investment risk, investors generally diversify and form an investment portfolio consisting of several assets. The problem is the fiery proportion of funds that must be allocated to each asset in the formation of investment portfolios. This paper aims to study the optimization of the Markowitz investment portfolio. In this study, the Markowitz model discussed is that which considers risk tolerance. Optimization is done by using the Lagrangean Multiplier method. From the study, an equation is obtained to determine the proportion (weight) of fund allocation for each asset in the formation of investment portfolios. So by using these equations, the determination of investment portfolio weights can be determined by capital.

Determination of crop insurance premiums in the Citarum River basin can be calculated by mathematical methods. One of the methods of calculation of the premium that is the normal curve methods with data on crop productivity is assumed to be Gaussian. In this thesis are discussed in crop insurance premium calculations Areas Citarum River basin West Bandung Regency with normal curve method with a significant level of coverage. These methods are used because data on crop productivity gained Gaussian. Normal curve method is used without using the assumption of coefficients of variation, and try for some level of coverage. Application materials used are rice crop productivity data in the Citarum River basin of West Bandung Regency in 2008-2014. This research resulted in the value of the rice crop insurance premiums for farmers in the area based on a certain level of coverage.