Final answer:
To add each of the words 'palmistry', 'etymology', 'paleontology', and 'glaciology' to the search tree, 2 comparisons are needed for each word. The comparisons are based on the location in alphabetical order compared to the existing words in the tree.
Step-by-step explanation:
When adding words to a search tree, you make comparisons at each node starting from the root of the tree. The number of comparisons depends on the position of the word in the alphabetical order relative to the other words. Let's solve this step by step for each word.
palmistry: It falls between 'alchemy' and 'oenology' in alphabetical order. Starting fresh each time, first, compare it with 'alchemy'. Since 'palmistry' comes after 'alchemy', we move to the next comparison with 'oenology', before which 'palmistry' fits. So, 2 comparisons are needed.
etymology: This word comes after 'alchemy' but before 'campanology'. Therefore, first compare it with 'alchemy', and then with 'campanology'. Hence, 2 comparisons as well.
paleontology: It will be compared with 'oenology' first since it starts with 'p'. Then it should be compared with 'phrenology' because it comes after 'oenology' but before 'phrenology'. Thus, 2 comparisons are needed.
glaciology: Coming before 'ichthyology' but after 'campanology', the word 'glaciology' will be compared first with 'campanology', then with 'ichthyology'. Therefore, it requires 2 comparisons as well.