Answer:
do not agree
Explanation:
For student A
[tex]B=4.2\pm 0.8\ T\\\Rightarrow B=4.2+0.8\ or\ B=4.2-0.8\\\Rightarrow B=5\ T\ or\ 3.4\ T[/tex]
The magnetic field measured by student A = 5 T or 3.4 T
For student B
[tex]B=5.6\pm 0.5\ T\\\Rightarrow B=5.6+0.5\ or\ B=5.6-0.5\\\Rightarrow B=6.1\ T\ or\ 5.1\ T[/tex]
The magnetic field measured by student B = 6.1 T or 5.1 T
The magnetic fields measured are not equal hence they do not agree.