Question

1. The process that makes the spaghetti noodles for Delectable Delights is supposed to produce noodles with an average length of 252 mm.   Allison, the Quality Control Manager, is concerned that Machine #42 is not working properly and the noodles it produces are too short.  You are asked to take a random sample of 40 noodles from Machine #42 and perform a hypothesis test to determine if the noodles produced by the machine are, on average, less than 252 mm.  Use a significance level of 5%.

2. Define  in the context of the problem and state the appropriate hypotheses. (10 pts)
   1. The population mean, µ = mean length of the spaghetti noodles for Delectable Delights is 252mm.
   2. µ = 252mm
   3. The null and alternative hypotheses:
   4. H0: µ = 252
   5. Ha: µ < 252

JMP Output for Hypothesis Test:

Hypothesized Value	252
Actual Estimate	250.95
DF	39
Std Dev	2.74516

	t Test
Test Statistic	-2.4191
Prob > |t|	0.0203*
Prob > t	0.9898
Prob < t	0.0102*

Test Statistic: -2.4191

P-value or Rejection Region: 0.0203

2. What is your decision regarding the null hypothesis? (In other words, do you reject or fail to reject and why?) (5 pts)

3. Write a final concluding statement to Allison giving the results of the hypothesis test. (In other words, write the final summary statement.) (5 pts)

Answer 1