19. Arranging Objects The following data are the response times in seconds for n525 first graders to arrange three objects by size.

a. Find the mean and the standard deviation for these 25 response times.

b. Order the data from smallest to largest.

c. Find the z-scores for the smallest and largest response times. Are these times unusually large or small? Explain.

5.2 3.8 5.7 3.9 3.7 4.2 4.1 4.3 4.7 4.3 3.1 2.5 3.0 4.4 4.8 3.6 3.9 4.8 5.3 4.2 4.7 3.3 4.2 3.8 5.4