A quality control engineer chooses a simple random sample of n =35 bottles of beer from a machine which fills bottles of beer. He records the number of ounces of beer in each bottle, and uses the data to calculate the 95% confidence interval estimate of the mean number of ounces of beer in all bottles filled by that machine. The result is: Lower bound 11.92 oz. Upper bound 12.06 oz. It is not correct to say "The probability is 95% that the population mean is between 11.92 oz 12.06 oz." What does the 95% actually refer to