At a particular university, students' grades in introductory statistic classes are generally unimodal and skewed to the left with a mean of / = 61 and a standard deviation of o = 20.0. (Round your answers to four decimal places, if needed.) (a) The distribution of students' grades is is approximately normal (b) If n = 34 students are selected at random, the distribution of the sample mean grade is approximately normal * with a mean of and a standard deviation of (c) The probability that the sample mean grade for these 34 students is less than 67.0 is (d) If n = 34 students are selected at random, the distribution of the sample total grade is approximately normal = with a mean of and a standard deviation of (e) The probability that the total grade for these 34 students is less than 2278.0 is Check