H0SolutionThe degree of freedom n128127 It is a lefttailed t

H₀:

Solution

The degree of freedom =n-1=28-1=27

It is a left-tailed test.

Given a=0.05, the critical value is t(0.05, df=27) =-1.703 (from student t table)

Answer:- 1.703

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Answer: One mean, two-tailed t test