Find the error intervals for the following rounded numbers

Question 1:

50000 (1 s.f.)

45000≤x<55000

Question 2:

0.485 (3 s.f.)

0.4845≤x<0.4855

Question 3:

0.07 (1 s.f.)

0.065≤x<0.075

Question 4:

0.28 (2 s.f.)

0.275≤x<0.285