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Unbiased estimate of population mean 
Unbiased estimate of population variance 
Let 
be the population mean time required by an employee to complete a task.
against
at 10% level of significance
Reject 
if p-value 
Test Statistic, 
Applying t-test with 
From GC, 
, reject .
Thus, there is sufficient evidence at 10% significance level that there has been a change in the mean time required by an employee to complete the task.
