Here is the actual Prosper Loan Analyzer that I use when evaluating a single loan. For input it takes the credit grade, debt to income ratio, and loan amount. It looks at all loans in the last 100 days with the same credit grade, DTI 0% to DTI+10%, and loan amount +/- $5,000 dollars. It returns a graph of the average interest rate by loan amount and calculates the number of loans, average amount borrowed, weighted average interest rate by amount borrowed, and the standard deviation of the interest rate. Give it a try. FYI: Prosper loans are from $1,000 to $25,000 dollars.