The answer to this question is "Data analysis". The production manager is gathering information and investigating the mean lifetime of each of the 10 bulbs. As a result of his study, he found out that the mean lifetime of light bulbs is 442 hours. Since we know the data is analysis is the process of gathering information and establishing reliable outcomes so the answer to this problem is Data analysis.
A production manager tests 10 lightbulbs and finds their mean lifetime is 442 hours. She then designs a sales package for this type of bulb. It states that consumers can expect the bulb to last approximately 450 hours. This is an example of what phase of inferential statistics?