Now consider a sample that consists of four spheres, each with a different mass: blue mass is 4.00 g, red mass is 3.75 g, green mass is 3.00 g, and yellow mass is 1.25 g.
• a. Calculate the average mass of a sphere in this sample.
• b. How does the average mass for a sphere in this sample compare with the average mass of the sample that consisted just of the blue spheres? How can such different samples have their averages turn out the way they did?