A safety auditor at a paint factory took a random sample of 25 cans of paint from a production run of over 1000 cans and measured the amount of lead in each can of paint in the sample. The sample data were approximately Normal with a mean of 37 parts per million (ppm) of lead per can, and a standard deviation of 18 ppm. Based on this sample, what is the 95 percent confidence interval for the mean amount of lead per can of paint (in ppm) in this production run?