Answer:
Z - statistic = 0.25
P-value
P(Z=0.25) = 0.802587
The result is not significant at p<0.01
Step-by-step explanation:
Step(i):-
Given the random sample size 'n'' = 400
A random sample of 400 items where 82 were found to be defective
Sample proportion
[tex]p = \frac{x}{n} = \frac{82}{400} = 0.205[/tex]
Given Population proportion
P = 0.20
Null Hypothesis : P = 0.20
Alternative Hypothesis : P≠ 0.20
Step(ii):-
Test statistic
[tex]Z = \frac{p-P}{\sqrt{\frac{PQ}{n} } }[/tex]
[tex]Z = \frac{0.205-0.20}{\sqrt{\frac{0.20X0.80}{400} } }= \frac{0.005}{0.02} =0.25[/tex]
Z - statistic = 0.25
Level of significance =0.01
P-value
P(Z=0.25) = 0.802587
Conclusion:-
The result is not significant at p<0.01