You started planning for your retirement. Assume a fixed horizon (given below) and a given annual inflation rate. For the first years you will be making contributions at the beginning of the year (adjusted for the inflation beginning in year 2) in order to meet the following retirement goal: Starting in year K, withdraw a desired amount (IN TODAY'S DOLLARS) at the beginning of each year until the end of the horizon. For the first few years, you will be using more aggressive investments (higher expected return). For the next few years assume a different return another for the remainder of the years. Build a model to answer the question: What is the minimum first contribution to accomplish such a retirement goal