By law of refraction we know that image position and object positions are related to each other by following relation
[tex]\frac{\mu_1}{h_o} = \frac{\mu_2}{h_i}[/tex]
here we know that
[tex]\mu_1 = 1.473[/tex]
[tex]h_o = 5 cm[/tex]
[tex]\mu_2 = 1[/tex]
now by above formula
[tex]\frac{1.473}{5} = \frac{1}{h_i}[/tex]
[tex]h_i = 3.39 cm[/tex]
so apparent depth of the bottom is seen by the observer as h = 3.39 cm
