Find the error intervals for the following rounded numbers

Question 1:

0.0004 (1 s.f.)

0.00035≤x<0.00045

Question 2:

2.4 (1 d.p.)

2.35≤x<2.45

Question 3:

54 (2 s.f.)

53.5≤x<54.5

Question 4:

0.02 (1 s.f.)

0.015≤x<0.025