The weights of adult chipmunks vary according to a normal distribution with standard deviation 1.4 ounces. Researchers suspect that the mean weights of populations of chipmunks depend on where they live. A team of biologists caught, weighed, and released 15 chipmunks in Rocky Mountain National Park, and the mean weight for this sample was 8.2 oz. Which of the following is a 96% confidence interval for the true mean weight of chipmunks in the park? and, Researchers want to estimate the mean weight of all chipmunks living in Albuquerque, NM. Using the population standard deviation of 1.4 ounces, find the sample size required if we want our margin of error to be less than 0.25 ounces with 95% confidence.