Because of new studies documenting toxic off-gassing from vinyl shower curtains, Arborgrass Consulting also recommended Bates consider a new line of organic shower curtains made from bamboo and hemp. Bates is intrigued, but he's worried whether he can afford it or not. Shower curtains at the Bates Motel are frequently getting ripped, and Bates incurs significant costs to replace them.

On second thought, Bates doesn't know if "half" is correct. He looked through his records, and found that of the most recent 210 guest visits at the motel, the shower curtain has been ripped and required replacement 115 times.

Obtain a 95% confidence interval for the true proportion of guest visits that result in a ripped shower curtain.