Major League Baseball Rule 1.09 states that "the baseball shall weigh not less than=or more than=1⁄4 ounces" (www.mlb.com). Use these values as the lower and the upper control limits, respectively. Assume the centerline equals 5.125 ounces. Periodic samples of 50 baseballs produce the following sample means:

a. Construct an x chart. Plot the sample means on the x chart.

b. Are any points outside the control limits? Does it appear that the process is under control? Explain.