Suppose a certain species bird has an average weight of x = 3.2 grams. Based on previous studies we can assume that the weights of these birds have a normal distribution with sigma = 0.34 grams. For a...

Suppose a certain species bird has an average weight of x = 3.2 grams. Based on previous studies we can assume that the weights of these birds have a normal distribution with sigma = 0.34 grams. For a small group of 18 birds , find a 98% confidence interval for the average weights of these birds. Write answer in interval notation with two decimal places.