One hundred professors attended a seminar on online instruction. The attitudes of a representative sample of 15 of the professors were measured before and after the seminar. A positive number for change in attitude indicates that a professor's attitude toward online teaching became more positive. The 15 change scores are as follows: 3; 8; -2; 7; 8; 5; 4; 1; 0; 6; 7; -2; -1; -2; 5.

Answer the following questions (round to 2 decimal spaces):

1. What is the mean change score?
2. What is the standard deviation for this sample?
3. What is the median change score?
4. What is the mode?
5. Find the change score that is 1 standard deviation below the mean.