Dangerous room rate = 1998-1999 =0.3%

1. 1998 building area: 104070-4747=99323 square meters,

1998 dangerous room rate: 741.4104070+0.3% ≈1%.

1998 dangerous building area: 99323 *1%≈ 993.23m2.

The first one is correct,

The second mistake is that the total housing area has changed, and the denominator of the dangerous house rate in 1999 is different from that in 1998.