Question

1. A machine produces metal rods used in an automobile suspension system. A random sample of 15 rods is selected, and the diameter is measured (in millimeters).

Diameter
8.24
8.21
8.23
8.25
8.26
8.23
8.2
8.26
8.19
8.23
8.2
8.28
8.24
8.25
8.24

Using RStudio, find and interpret a 95% confidence interval (CI) for the true mean diameter (in millimeters) of metal rods used in an automobile suspension system.

1. Label the parameter: (4 points)

2. Propose an appropriate confidence interval. Explain! (3 + 1 = 4 points)

3. Verify the required conditions for the proposed confidence interval: (8 points)

Note: Describe the required conditions in context:

Note: Attach your R codes and normal QQ plot in the following space:

4. Report a 95% confidence interval for the true mean diameter (in millimeters) of metal rods used in an automobile suspension system: (3 points)

Note: Report CI (2 decimal places):

Note: Attach your R codes in the following space:

5. Interpret a 95% confidence interval for the true mean diameter (in millimeters) of metal rods used in an automobile suspension system in context: (6 points)

Answer 1