A production line produces rulers that are supposed to be 12 inches long. A sample of 49 of the rulers had a mean of 12.1 and a standard deviation of .5 inches. The quality control specialist responsible for the production line decides to two-sided hypothesis test to determine whether the production line is really producing rulers that are 12 inches long or not.
a) What is the null hypothesis?
Ho: u=12
b) What is the alternative hypothesis
H1:
c) Using whatever method, you want, clearly run and summarize the result of the hypothesis test. What does this mean in terms of the problem situation?
Tstat= x'- Uo/(s/ ) 12.1-12/(.5/ ) = 1.49 .5/.7 = 1.400
Do not reject the null hypothesis. There is no evidence that the average length of the rulers is different inches.