A 3 year asset swap spread is 100 basis points (pay able semiannually). Suppose that a 3 year corporate bonds provide a coupon of 7% per year semiannually. The yield for all maturities on risk free bond is 4% per annum (expressed with semiannual compounding). Assume that defaults can take places every 6 month (immediately before a coupon payment) and that the recovery rate is 45%. Estimate default probabilities that assuming (a) unconditional default probabilities are the same on each possible default date, and (b) that default probabilities conditional on no earlier default are the same on each possible default date