Answer:
a
The 95% confidence interval is
Generally the interval above can interpreted as
There is 95% confidence that the true proportion of Wal-Mart stores that have more than 2 items priced inaccurately per 100 items scanned lie within the interval
b
Generally 99% is outside the interval obtained in a above then the claim of Wal-mart is not believable
c
Step-by-step explanation:
From the question we are told that
The sample size is n = 60
The number of stores that had more than 2 items price incorrectly is k = 52
Generally the sample proportion is mathematically represented as
=> 
=> 
From the question we are told the confidence level is 95% , hence the level of significance is
=> 
Generally from the normal distribution table the critical value of 
is
Generally the margin of error is mathematically represented as
=> 
=> 
Generally 95% confidence interval is mathematically represented as
=> 
=>
Generally the interval above can interpreted as
There is 95% confidence that the true proportion of Wal-Mart stores that have more than 2 items priced inaccurately per 100 items scanned lie within the interval
Considering question b
Generally 99% is outside the interval obtained in a above then the claim of Wal-mart is not believable
Considering question c
From the question we are told that
The margin of error is E = 0.05
From the question we are told the confidence level is 95% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of is
Generally the sample size is mathematically represented as
![n = [\frac{Z_{\frac{\alpha }{2} }}{E} ]^2 * \^ p (1 - \^ p )](https://tex.z-dn.net/?f=n%20%3D%20%5B%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%7D%7D%7BE%7D%20%5D%5E2%20%2A%20%5C%5E%20p%20%281%20-%20%5C%5E%20p%20%29%20)
=> ![n= [\frac{1.645 }}{0.05} ]^2 * 0.867 (1 - 0.867 )](https://tex.z-dn.net/?f=n%3D%20%20%5B%5Cfrac%7B1.645%20%7D%7D%7B0.05%7D%20%5D%5E2%20%2A%200.867%20%20%281%20-%200.867%20%29%20)
=>
