You measure 50 watermelons' weights, and find they have a mean weight of 79 ounces. Assume the population standard deviation is 12.4 ounces. Based on this, construct a \( 99 \% \) confidence interval for the true population mean watermelon weight. Use \( z \) for the critical value.
Give your answers as decimals, to two places
\( \pm \) \( \square \) ounces