Answer:
1.33
Explanation:
For an optical instrument, the magnification ratio of the apparent diameter of the image to that of the object.
Mathematically, from the given information;
Magnification[tex]= \dfrac{n_{water}}{n_{air}}[/tex]
where;
[tex]n_{water} =1.33\\ \\ n_{air} = 1.00[/tex]
[tex]= \dfrac{1.33}{1.00} \\ \\= \mathbf{1.33}[/tex]