At a particular university, students' grades in introductory statistic classes are generally unimodal and skewed to the left with a mean o f= 68 and a standard deviation of= 19.0. (Round your answers to four decimal places, if needed.)

(b) Ifn= 39 students are selected at random, the distribution of the sample mean grade is:____ (a. approximately normal b. not normal c. left-skewed d. right skewed) with a mean of:____ and a standard deviation of:___

(c) The probability that the sample mean grade for these 39 students is less than 70.0 is:______

(d) Ifn= 39 students are selected at random, the distribution of the sample total grade is:___(a.approximately normal b. not normal c. left-skewed c. right-skewed) with a mean of:___and a standard deviation of:___

(e) The probability that the total grade for these 39 students is less than 2730.0 is:____