Use the data in the following table showing cumulative default rates for years relative to the issuance of a bond.

t=TIme in Years Relative to Date of Issue

Rating	1	2	3	4	5	7	10	15	20
Aaa	0.000	0.013	0.013	0.037	0.104	0.241	0.489	0.910	1.073
Aa	0.022	0.068	0.136	0.260	0.410	0.682	1.017	1.871	3.167
A	0.062	0.199	0.434	0.679	0.958	1.615	2.759	4.583	7.044
Baa	0.174	0.504	0.906	1.373	1.862	2.872	4.623	8.306	11.989
Ba	1.110	3.071	5.371	7.839	10.065	13.911	19.323	28.500	35.410
B	3.904	9.274	14.723	19.509	23.869	31.774	40.560	50.275	55.892
Caa_C	15.894	27.003	35.800	42.796	48.828	56.878	66.212	73.152	74.946

data in percent

What is the probability a Baa rated bond will survive past year 4?

Estimate the hazard rate (default intensity, ) of a Baa rated bond based on the 3-year cumulative default probability

Estimate the hazard rate (default intensity, ) of a Baa rated bond based on the 4-year cumulative default probability

Compute the probability of default for a Baa rated bond during year 4 given that the bond has not defaulted by the end of year 3

Explain why your answers in b. and c. are not the same as in d.