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Question: Light bulbs have lifetimes that are known to be approximately normally distributed. Suppose a random...

Question: Light bulbs have lifetimes that are known to be approximately normally distributed.
Suppose a random sample of 35 light bulbs was tested, and = 943 hours and s = 33 hours.

a. Find a 90% confidence interval for the true mean life of a light bulb.
b. Find a 95% lower confidence limit for the true mean life of a light bulb.
c. Are the results obtained in (a) and (b) the same or different? Explain why.
Math   Statistics-And-Probability   
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