1. A factory manufacturing light emitting diode (LED) bulbs claims that their light bulbs last for 50,000 hours on the a

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1 A Factory Manufacturing Light Emitting Diode Led Bulbs Claims That Their Light Bulbs Last For 50 000 Hours On The A 1 (82.07 KiB) Viewed 106 times

1. A factory manufacturing light emitting diode (LED) bulbs claims that their light bulbs last for 50,000 hours on the average. To confirm if this claim is valid, a quality control manager obtained a random sample of 50 LED light bulbs and got a mean lifespan of 40,000 hours. The standard deviation of the manufacturing process is 1000 hours. a. What is the best point estimate for the true mean lifespan of LED light bulbs manufactured by this company? b. What is the standard error of this point estimate? c. What is the margin of error of this point estimate @ 95% confidence level? d. Construct a 95% confidence interval of the true mean lifespan of LED light bulbs manufactured by this company. e. Do you think that the claim of the manufacturer is valid? Explain. f. If you want to be 99% confident that the point estimate is at most 100 hours from the true mean life span, how many light bulbs should be included?