The standard deviation of the weights of elephants is known to be approximately 15 pounds. We want to construct a 95% confidence interval for the mean weight of newborn elephant calves. 50 newborn elephants are weighed. The sample mean is 244 pounds. The sample standard deviation is 11 pounds.

1. Identify:

x =244

=15

n =50

2. Which distribution should you use for this problem?

3. What will happen to the confidence interval obtained if 500 newborn elephants are weighed instead of 50? Why?