A home building company routinely orders standard interior doors with a height of 80 inches. Recently the installers have complained that the doors are not the standard height. The quality control inspector for the home building company is concerned that the manufacturer is supplying doors that are not 80 inches in height. In an effort to test this, the inspector is going to gather a sample of the recently received doors and measure the height. The alternative hypothesis for the statistical test to determine if the doors are not 80 inches is
A.
the mean height is > 80 inches
B.
the mean height is < 80 inches
C.
the mean height is = 80 inches
D.
the mean height is ≠ 80 inches
E.
the mean height is ≥ 80 inches