Use the Following Information for Questions

Short Answer

Use the following information for questions:
The distribution of quiz, exam, and course grades is known to be left-skewed. The course grades (measured as percentage scores) in upper level statistics classes have a mean of 68 with a standard deviation of 15.
-Suppose 50 course grades are to be randomly selected and the average score in the sample calculated. What is the standard deviation of the sampling distribution of the average percentage score in the sample of 50 course grades?