In a random sample of 725 selected for interview from your database of 13,916 customers, 113 said they are dissatisfied with your company’s service.
a. Find the best estimate of the percentage of all customers in your entire database who are dissatisfied.
b. Find the standard error of your estimate of the percentage of all customers who are dissatisfied.
c. Find the best estimate of the overall number of dissatisfied customers within your database.
d. Find the 95% confidence interval for the percentage of dissatisfied customers.
e. The company’s goal has been to keep the percentage of dissatisfied customers at or below 10%. Could this reasonably still be the case, or do you have convincing evidence that the percentage is larger than 10%? Justify your answer.