Answer:
The required sample size 'n' = 97 .41 hours
Step-by-step explanation:
Explanation:-
Given standard deviation of the Population 'Ļ' = 3 hours
Given the Margin of error = [tex]\frac{1}{2} hour[/tex]
The Margin of error is determined by
[tex]M.E = \frac{Z_{\frac{\alpha }{2} S.D} }{\sqrt{n} }[/tex]
Given level of significance ā = 0.10 or 0.90
Zā.āā = 1.645
[tex]\frac{1}{2} =\frac{1.645 X 3}{\sqrt{n} }[/tex]
Cross multiplication , we get
[tex]\sqrt{n} = 2 X 1.645 X 3[/tex]
ān = Ā 9.87
Squaring on both sides, we get
n = 97.41 hours
Final answer:-
The required sample size 'n' = 97.41 hours
