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
=>
=>
