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
![\^ p = \frac{ k }{ n }](https://tex.z-dn.net/?f=%5C%5E%20p%20%20%3D%20%20%5Cfrac%7B%20k%20%7D%7B%20n%20%7D)
=> ![\^ p = \frac{ 52 }{ 60 }](https://tex.z-dn.net/?f=%5C%5E%20p%20%20%3D%20%20%5Cfrac%7B%2052%20%7D%7B%2060%20%7D)
=> ![\^ p = 0.867](https://tex.z-dn.net/?f=%5C%5E%20p%20%20%3D%20%200.867)
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
=>
=>