Specifications for a part for a 3-D printer state that the part should weigh between 24.5 and 25.5 ounces. The process that produces the parts has a mean of 25.0 ounces and a standard deviation of .25 ounce. The distribution of output is normal. Use Table-A.

a.What percentage of parts will not meet the weight specs? (Round your “z” value and final answer to 2 decimal places.)

b.Within what values will 99.74 percent of the sample means of this process fall if samples of n = 8 are taken and the process is in control (random)? (Round your answers to 2 decimal places.)

lower value: upper value:

c. Using the control limits from part b, would the following sample means be in control? 24.52, 24.53, 24.44, 24.51, 24.41, 24.39

• This process is in control.

• This process is not in control.