Noise The manufacturing industry is concerned about the health of workers exposed to loud noises in factories. 3 For this example, an experiment tested samples of 24 employees in four auto assembly...

Noise The manufacturing industry is concerned about the health of workers exposed to loud noises in factories.³
For this example, an experiment tested samples of 24 employees in four auto assembly plants for elevated blood pressure. The environment was described as normal (averaging 65 dB), moderate (80 dB), and loud (95 dB).

(a) The workers were not randomly assigned to the different tasks or assembly plants. Is that a problem? Why or why not?

(b) The experiment recorded the change in blood pressure from a baseline established for each employee. Would it have been better to use the blood pressure itself rather than the change?

(c) Is the data balanced? Explain.

(d) What does the profile plot indicate? Which factor belongs on the
-axis?

(e) Perform the two-way ANOVA. What conclusions do you draw from the ANOVA summary table?