[Steps Shown] Let x be the random variable that represents assembly time for the Ford Taurus. The average assembly time for the Ford Taurus is µ = 38 hours.
Question: Let x be the random variable that represents assembly time for the Ford Taurus. The average assembly time for the Ford Taurus is µ = 38 hours. A modification to the assembly procedure has been made. It is thought that the average assembly time may be reduced because of this modification. A random sample of 47 new Ford Taurus automobiles coming off the assembly line showed the average assembly time to be \(\bar{X}\) = 37.5 hours with sample standard deviation s = 1.2 hours. Does this indicate that the average assembly time has been reduced? Use \(\alpha =0.01\)
- What is the null hypothesis? What is the alternate hypothesis? Will we use a left-tailed, right-tailed, or two-tailed test? What is the level of significance?
- What sampling distribution will we use? What is the critical value z o (or critical values ± z o)
- Sketch the critical region and show the critical value (or critical values).
- Calculate the z value corresponding to the sample statistic \(\bar{X}\) and show it’s location on the sketch of part (c)
- Based on your answers for parts (a) to (d), shall we reject or fail to reject (i.e., "accept") the null hypothesis at the given level of significance \(\alpha \) ? Explain your conclusion in the context of the problem.
- Are the data statistically significant?
Deliverable: Word Document 