The image of one kind of United States postage stamp is 3.70 times the size of the actual stamp in front of a lens. Find the focal length of the lens if the dis- tance from the lens to the stamp is 2.81 cm. 1. 3.89015 2. 3.85074 3. 3.29651 4. 6.67909 5. 3.17091 6. 3.66138 7. 6.93397 8. 4.24386 9. 4.03566 10. 6.47294 Answer in units of cm