Confidence interval for the process mean lifetime

Assignment Help Engineering Mathematics

Reference no: EM13823639

A quality control manager at factory manufacturing high intensity light bulbs which have relatively short lifetime but maintain their intensity during their lifetime needs to estimate the average life of a light bulb. It is known that the process lifetime is normally distributed and has a standard deviation of 180 hours. A sample of 20 light bulbs gives a mean life of 236 hours.

a. Find a 95% confidence interval for the process mean lifetime and give an interpretation of this interval.

b. What sample size needs to be used if the mean lifetime is to be estimated within an error of plus or minus 24 hours with probability 0.9?

Reference no: EM13823639

Questions Cloud

Write on drug abuse negatively impacts academic performance : Write Full Sentence Outline about Drug abuse negatively impacts academic performance. A full sentence outline will build on the information you presented in your research proposal.

One-tailed test of hypothesis versus upper one-tailed test : How can you determine when to use a lower one-tailed test of hypothesis versus an upper one-tailed test?

Protect the reputation of the members : The ACS Disciplinary Committee has decided to hold its meetings In Camera, and not make available the results of their determinations to the complainants, or the general membership. This, they say, is to protect the reputation of the members who c..

What is the process of memory from perception to retrieval : What is the process of memory from perception to retrieval

Confidence interval for the process mean lifetime : Find a 95% confidence interval for the process mean lifetime and give an interpretation of this interval.

Explain the role of training in an organization development : Identify two jobs within your assigned company. (houskeeping supervisor and reservations supervisor) Describe the general function of performance management systems. If your assigned company does not use a performance management system, would you rec..

The scientific method paper : The Scientific Method paper

Describe the market positioning : Discussion #1 Describe the market positioning (for total rewards) of at least two organizations. Use a minimum of 2 references and interact with at least 1 classmate.

What should be taught to students between ages fourteen : Write a dialogue in which Socrates, Descartes, and Galileo discuss what should be taught to students between the ages of 14-18.

User Account

All Pages