Suppose that an eBay power seller has had an average customer approval score of 83.4 out of a total of 100 points for the past 6 or 7 years. This year, the seller decided to offer free shipping in order to boost the approval score.
The seller offered free shipping to 25 customers for randomly selected products and then collected and reviewed the customers' approval scores. What type of statistical analysis is most appropriate to determine whether the offering of free shipping resulted in a significant increase in approval score?
- One-sided, Single Population Hypothesis Test
- Two-sided, Single Population Hypothesis Test
- One-sided, Two Population Hypothesis Test
- Two-sided, Two Population Hypothesis Test