Following up on the pen production, the quality control supply chain analyst would also like to make an enquiry on a pos

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Following up on the pen production, the quality control supply
chain analyst would also like to make an enquiry on a possible
difference in the production numbers over time. Assuming the pen
production is normally distributed, historical data report that
around 265 pens were produced per hour. Recently, on a sample of 48
hours, the average amount of pens is around 266 with an associated
variance of 8. The quality control supply chain analyst would like
to know if something has changed over recent times. Please perform
a hypothesis test for the population mean with a level of
significance of 0.05 while answering the following
questions.