If a sample of 25 fish from my pound has mean weight 157 grams with a standard deviation of 8.3 grams and we know the population standard deviation for the fish in my pond is actually 9.4 grams, then...

If a sample of 25 fish from my pound has mean weight 157 grams with a standard deviation of 8.3 grams and we know the population standard deviation for the fish in my pond is actually 9.4 grams, then WHAT IS the Margin of error in the 99 percent confidence interval for true mean weight of fish in my pond?