A catalog sales company promises to deliver orders placed on the Internet within 3 days. Follow-up calls to a few randomly selected customers show that a 95% confidence interval for the proportion of all orders that arrive on time is 88% ± 6%. What does this mean? Are the conclusions in parts a-e correct? Explain.
a) Between 82% and 94% of all orders arrive on time.
b) 95% of all random samples of customers will show that 88% of orders arrive on time.
c) 95% of all random samples of customers will show that 82% to 94% of orders arrive on time.
d) The company is 95% sure that between 82% and 94% of the orders placed by the customers in this sample arrived on time.
e) On 95% of the days, between 82% and 94% of the orders will arrive on time.