An app developer seeks to decide between a green and a blue version of a retail app. The developer releases a beta version of the app, and a user who downloads the app is randomly given the green or the blue version. A week after the download, the average time spent on the retail app by the 105 individuals who downloaded the green version and the 103 individuals who downloaded the blue version were, respectively, 14 minutes (SD = 3.3 minutes) and 11 minutes (SD = 3.1 minutes)
What is a 80% confidence interval for the difference between the average time spent by users on the green version of the app and the average time spent by users on the blue version of the app?