Question

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

Answer 1

Answer: Alternative Hypothesis

Ha : u ≠ 80 inches ( mean not equal to 80 inches)

Explanation:

The null hypothesis (H0) tries to show that no significant variation exists between variables or that a single variable is no different than its mean.

While an alternative Hypothesis (Ha) attempt to prove that a new theory is true rather than the old one. That a variable is significantly different from the mean.

For the case above, the mean door height is 80 inches

H0 : u = 80 inches

Ha : u ≠ 80 inches ( mean not equal to 80 inches)