One hundred teachers attended a seminar on mathematical problem solving. The attitudes of a representative sample of 1212of 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 1212change scores are as follows:

22;66;11;22;00;55;3-3;11;11;66;55;22

(a) What is the mean change score? Round your answer to two decimal places. x=x=

(b) What is the standard deviation for this sample? Round your answer to two decimal places. s=s=

(c) What is the median change score?

(d) Find the change score that is 2.22.2 standard deviations below the mean. Round your answer to two decimal places.