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...

Extracted text: 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. 4; 9; -1; 1; 0; 4; –2; 2; –1; 5; 4; –3 O Part (a) What is the mean change score? (Round your answer to two decimal places.) O Part (b) What is the standard deviation for this mple? ound your answer to two decimal es.) O Part (c) What is the median change score? (Round your answer to one decimal place.) O Part (d) Find the change score that is 2.2 standard deviations below the mean. (Round your answer to one decimal place.)