2. a. What is the difference between degree of confidence and confidence interval?
b. Provide a sketch of sample data that are associated with (i) an unbiased and efficient estimate of the mean and (ii) a biased and inefficient estimate of the mean.
c. Write an example of a confidence statement, with supporting sketches, that illustrates each of the following situations: (i) large confidence interval but large degree of confidence and (ii) small confidence interval but small degree of confidence.