Question

PLEASE HELP WITH SIGNIFICANT FIGURES *AWARDING BRAINEST ANSWER* ASAP

Answer 1

1) 0.07 zeros only matter if there is a non-zero digit, as well as the decimal to the left of it
2)90,000 it would have been 89000 if the 972 had been an 872
3).00420 must include the last zero, it is considered significant because of the reason in number one