What would be the work process to get the answer shown in blue?

1. ].R.R. Tolkien wrote in his epic novel The Lord of the Rings that the One Ring \"...did not seem always of the same size or weight; it shrank and expanded in an odd way... \" For instance, in Peter Jackson's lm adaptation of The Fellowship of the Ring, Isildur cut the One Ring from the hand of the Dark Lord Sauron during the final battle on the slopes of Mount Doom, and once the ring was removed from the severed finger of Sauron, it contracted to the size of a large male nger, which is about 25 mm in diameter. Let's assume the ring changes size according to thermal expansion and was made of a material with a coefcient of thermal expansion of 40 X 10'5 Kl. Suppose, too, that Suaron, who is often pictured to be standing in re or lava, has a temperature of 1100 \"'0. If the ring cools to a temperature of 30 C when it contracts, what is the diameter of Sauron's nger if we assume the ring fit snugly before it was removed? [Answer: (is 2 6.6 X 102 m]