Question

One hundred teachers attended a seminar on mathematical problem solving. The attitudes of a 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 12 change scores are as follows:

4; 9; −1; 2; 0; 5; −3; 1; −1; 6; 3; −2

1. What is the mean change score?
   
   Round your answer to two decimal places.
   
   xˉ=   
    

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

3. What is the median change score?
   
    
    

4. Find the change score that is 2.2 standard deviations below the mean.
   
   Round your answer to two decimal places.