The left end of a long glass rod 8.00 cm in diameter, with an index of refraction 1.60, is ground to a concave hemispherical surface with radius 4.00 cm. an object in the form of an arrow 1.40 mm tall, at right angles to the axis of the rod, is located on the axis 26.0 cm to the left of the vertex of the concave surface.

a) find the position of the image of the arrow formed by paraxial rays incident on the convex surface. (answer is s1 in units cm)
b) find the height of the image formed by paraxial rays incident on the convex surface. (answer is y1 in units mm)
c) is the image erect or inverted?
i have tried solving this problem multiple ways and even referred to previous answers, but nothing seems to work. i will rate lifesaver for anyone who shows a correct explanation of how to solve and approach this problem. i greatly appreciate any you can provide!