Olivia works at a company that creates mobile phones. She wanted to estimate the mean amount of time their new phone's battery lasts with regular use after a full charge. She took a random sample of 6 of these phones and randomly assigned each of them to a volunteer. She instructed them to fully charge the phones and use them as they regularly would until the battery died (without recharging the phone). Here are the data they reported:
Assume that all conditions for inference are met.
Which of the following is a 90% confidence interval for the mean battery life (in hours)?