Marcelina has over 500 500500 songs on her mobile phone, and she wants to estimate the average length of the songs (in minutes). She takes an SRS of 28 2828 songs on her phone and calculates a sample mean of 3.4 3.43, point, 4 minutes and a standard deviation of 0.72 0.720, point, 72 minutes. The song lengths in the sample were roughly symmetric with no clear outliers. Based on this sample, which of the following is a 99 % 99%99, percent confidence interval for the mean length (in minutes) of the songs on her phone?
