Question

Show all work. Use Minitab as much as you can.

Majority of problems from: Montgomery & Runger, 2007

Question 1:

The following data are the joint temperatures of the O-rings (degrees F) for each test firing or actual launch of the space shuttle rocket motor: 84, 49, 61, 40, 83, 67, 45, 66, 70, 69, 80, 58, 68, 60, 67, 72, 73, 70, 57, 63, 70, 78, 52, 67, 53, 67, 75, 61, 70, 81, 76, 79, 75, 76, 58, 31.

1. Compute the sample mean and sample standard deviation of the temperature data.
2. Graph a histogram of the data.
3. Graph a normal probability plot of the data.
4. Comment on the data

Question 2:

The mean water temperature downstream from a power plant cooling tower discharge pipe should be no more than 100 degrees F. Past experience has indicated that the standard deviation of temperature is 2 degrees F. The water temperature is measured on nine randomly chosen days, and the average temperature is found to be 98 degrees F.

1. Is there evidence that the water temperature is acceptable at α =0.05?
2. What is the p-value for this test?

Question 3:

Suppose that 1000 customers are surveyed and 850 are satisfied or very satisfied with a corporation’s products and services.

1. Test the hypothesis H₀: p = 0.9 against H₁: p ≠ 0.9 at α = 0.05. Find the p-value.
2. Explain how the question in part (a) could be answered by constructing a 95% two-sided confidence interval for p.

Answer 1