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Let be the population mean time taken to install an electronic component.
At 5% level of significance, we reject if
At 5% level of significance, we do not reject if
Some students forget to define appropriately. (ii), a few students actually do not realised that the rejection rule is when instead of , and did not consider the correct inequality. (iii), Students overlook that n refers to sample size and sample size must be an integer. The answers are required to be given in sets here. Some students still have trouble writing sets.