Reduced Level (R.L.) of the floor at building is 74.400 m, staff reading on the floor is 1.625 m and staff reading when it is held inverted with bottom touching the ceiling of a hall is 2.870 m, then the height of the ceiling above the floor is
1
3.593 m
2
3.953 m
3
4.594 m
4
4.495 m