a) Twenty-five adult black ducks from a large flock were trapped and weighed. Their mean weight was 1500g and the variance of their weights was 8100g ² . Find the 95% confidence intervals for the mean, variance , and standard deviation of the flock.

b) Dabbling ducks such as black ducks and mallards often have very skewed sex ratios. In the sample above, 10 were found to be females and the rest males. Use the information and the normal approximation of the binomial to generate a 95% confidence interval for the proportion of females in the flock.