Confidence interval and t test for mean life time
Always get overwhelmed by the amount of material when covered at a comprehensive level. Attached is the study material of what to be prepared to cover at the conclusion of this course. I have worked through them but get stumped at several points. Can you provide a systematic approach to these problems and provide a reference to refer to make sure my solutions are accurate. It would helpful if you can explain why you did what you did, as this is just a helpful of study and questions may appear differently at the actual conclusion of the course.
GE fluorescent bulbs have a useful lifetime which is normally distributed. We wish to estimate mean lifetime. A random sample of 20 bulbs yields the following results: sample mean= 2,360 hours and a sample standard deviation of 365 hours.
Refer to Table 8B on the Handout for MegaStat output.
Analyze the output above to determine the 95% confidence interval for the mean lifetime of GE fluorescent bulbs. Interpret this confidence interval.
Suppose a GE executive says. “Our florescent bulbs have an average expected lifetime of 2500 hours.” Could the executive be correct? Explain.