Explore BrainMass

Explore BrainMass

    Confidence Interval, Average expected Lifetime

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    See attached file.

    Pg 2-2

    A GE flourescent bulb's useful life is normally distrbuted. We wish to estimate the mean lifetime. A random sample of 15 bulbs are:

    2,222 hrs standard deviation of 310 hrs

    Refer to table 7A

    a) Determine 95% confidence interval
    b) If an executive can say the the average expected lifetime is 2,200, is he right?

    © BrainMass Inc. brainmass.com June 3, 2020, 11:59 pm ad1c9bdddf


    Solution Summary

    Complete, Neat and Step-by-step Answers are provided.