Question

Lightbulbs. A company produces lightbulbs. We know that the lifetimes (in hours) of lightbulbs follow a bell-shaped (symmetric and unimodal) distribution with a mean of 7,161 hours and a standard deviation of 564 hours. Use the Empirical Rule (68-95-99.7 rule) to answer the following question: The shortest lived 2.5% of the lightbulbs burn out before how many hours

Answer 1

Please find the complete question and its solution in the attached file.

Explanation:

Shortest had survived after 6741 hours
`2.5\%` of the lights burnt.

`\to 0.15\% + 2.35\% = 2.50\%`