From previous studies, it has been generally believed that Northern Hemisphere icebergs have a mean depth of 270 meters and a standard deviation of 20 meters. An environmentalist has suggested that global warming has caused icebergs to have greater depth. A team of scientists visiting the Northern Hemisphere observed a random sample of 41 icebergs. The depth of the base of the iceberg below the surface was carefully measured for each and the sample mean and standard deviation were calculated. Part a) Which of the following is/are parameter(s) of interest with respect to the new investigation here? (Select all that apply) A. The mean depth (in m) of all Northern Hemisphere icebergs. B. 20 meters C. The mean depth (in m) of the 41 icebergs in the study. D. 41 E. 270 meters F. The variance of the depths (in m) of all Northern Hemisphere icebergs. G. None of the above