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Writing hypotheses to test the difference of means


An exercise scientist wanted to test the effectiveness of a new program designed to increase the flexibility of senior citizens. They recruited participants and rated their flexibility according to a standard scale before starting the program. The participants all went through the program and had their flexibility rated again after a month.
The scientist wants to test if the flexibility ratings are significantly higher after a month of the program. Assume that these participants can be considered a representative sample and that all other necessary conditions for inference were met.
Which of these is the most appropriate test and alternative hypothesis?
Choose 1 answer: