Final answer:
The student's task is to horizontally center the content in selected cells, probably within a program like Microsoft Word or a spreadsheet application. The instructions regarding hanging indents are not directly applicable to centering content. Centering is usually done via the alignment options in the paragraph formatting section of the program.
Step-by-step explanation:
The student's question refers to the task of aligning the content of selected cells in a horizontal manner within a software application, likely a spreadsheet or a word processor. To center content horizontally, you would generally select the cells you want to modify, navigate to the formatting options, and choose the 'center' alignment. While the instructions provided mention formatting a hanging indent in Microsoft Word, centering content horizontally is a different function. The hanging indent instruction is more related to formatting a bibliography or references page. However, if you need to center the content horizontally instead, you should look for the alignment section within your paragraph formatting options, not the indentation options.