Help with grade 12 statistics question.?

Question by Jimmy Li: Help with grade 12 statistics question.?
Provide complete solutions.If someone is able to help me it would be awesome. :/

An industrial-safety inspector wishes to estimate the average noise level in decibels(dB) on a factory floor. she knows that the standard deviation is dB.She wants to be 90% confident that the estimate is correct within ±2 dB. How many noise-level measurements should she take.


Best answer:
Answer by Elizabeth MYou haven't given the standard

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