Parametric Estimation is a statistical technique used to estimate unknown parameters of a population based on sample data. It assumes that the data follows a specific distribution, such as the normal distribution, allowing for the calculation of estimates like means and variances. This method is widely used in fields like economics and engineering to make predictions and inform decision-making. In project management, parametric estimation helps in predicting project costs and durations by using historical data and established relationships. For example, if a similar project took 100 hours to complete, a project manager might estimate that a new project of similar scope will take approximately the same amount of time, adjusted for any differences.