please help with part b and d. thank you!

One hundred teachers attended a seminar on mathematical problem solving. The attitudes of representative sample of 12 of the teachers were measured before and after the seminar. A positive number for change in attitude indicates that a teacher's attitude toward math became more positive. The twelve change scores are as follows. 3; 8; 1; 2; 0; 5; 3; 1; 1; 6; 5; 2 What is the mean change score? (Round your answer to two decimal places.) _ :Whatjsthestapdard deviation for this sample? (Round your answer to two decimal places.) ' Entera number. What is the median change score? (Round your answer to one decimal place.) Iv Find the change score that is 2.2 standard deviations below the mean. (Round your answer to one decimal place.) Ix