A vet takes the weights of all of the puppies that come in at a specific age for a full month. He does not differentiate between dog breeds or gender. The following 20 values are the weights he records (in pounds):

10, 15, 7, 21, 11, 13, 9, 17, 14, 10, 11, 12, 25, 4, 9, 13, 16, 14, 12, 11

Find the sample mean, standard deviation, and confidence interval assuming an alpha value of 0.05.