SOLUTION: A light bulb manufacturer finds that 5% of his bulbs last more than 500 hours. An improvement in the process meant that the mean lifetime was increased by 50 hours . In a new test,
Algebra.Com
Question 1191723: A light bulb manufacturer finds that 5% of his bulbs last more than 500 hours. An improvement in the process meant that the mean lifetime was increased by 50 hours . In a new test, 20% of bulbs now lasted longer than 500 hours.
Find the mean and standard deviation of the original process
Answer by ikleyn(52780) (Show Source): You can put this solution on YOUR website!
.
Looking at this problem, I'd say that its formulation is incorrect (or incomplete).
Would it be correct and complete, it must say that the standard deviation after improvement remained the same as before it.
Since the problem is silent about it (leaving it for the reader to guess), this problem is more like a puzzle than a Math problem.
RELATED QUESTIONS
A light bulb manufacturer finds that 5% of his bulbs last more than 500 hours. An... (answered by Theo,ikleyn)
A light bulb manufacturer finds that 5% of his bulbs last more than 1000 hours. An... (answered by Boreal)
A light bulb manufacturer claims his light bulbs will last 500 hours on the average. The... (answered by stanbon)
a manufacturer of light bulbs claims that its new light bulb has a mean life of 1000... (answered by stanbon)
a manufacturer of light bulbs claims that its new light bulb has a mean life of 1,000... (answered by Fombitz)
A manufacturer of halogen light bulbs claims that the lives of the light bulbs are... (answered by stanbon)
Please help me solve this problem:
Suppose you are a buyer of large supplies of light (answered by stanbon)
Please help me.
t distribution related problem.
Acme corporation manufactures light... (answered by Positive_EV)
Life of Light Bulbs A certain type of light bulb has an average
life of 500 hours, with... (answered by stanbon)