Answer
The differences between the experimentally measured distances and the predicted distances:
$Li-F: 0.08$ angstrom
$Na-Cl: 0.01$ angstrom
$K-Br: 0.04$ angstrom
$Rb-I: 0.05$ angstrom
In the case of $Na-Cl$ and $K-Br$, the two sets are the same. In the case of $Li-F$ and $Rb-I$, the two sets are not.
Work Step by Step
The differences between the experimentally measured distances and the predicted distances:
$Li-F: 2.09-2.01=0.08$ angstrom
$Na-Cl: 2.83-2.82=0.01$ angstrom
$K-Br: 3.34-3.30=0.04$ angstrom
$Rb-I: 3.72-3.67=0.05$ angstrom
Assuming we have an accuracy of $0.04$ angstrom, then in the case of $Na-Cl$ and $K-Br$, the two sets are the same. But in the case of $Li-F$ and $Rb-I$, the two sets are not the same.
