To find the focal length of a convex mirror, a student records the following data: The focal length of the convex lens is f_1 and that of mirror is…

To find the focal length of a convex mirror, a student records the following data :

Object Pin	Convex Lens	Convex Mirror	Image Pin
$\displaystyle 22.2$ cm	$\displaystyle 32.2$ cm	$\displaystyle 45.8$ cm	$\displaystyle 71.2$ cm

The focal length of the convex lens is $\displaystyle f_1$ and that of mirror is $\displaystyle f_2$. Then taking index correction to be negligibly small, $\displaystyle f_1$ and $\displaystyle f_2$ are close to :