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8. A manufacturing company of light bulb claims that an average light bulb lasts 500 days. A contractor randomly selects 30 b

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Answer #1

Value is obtained from standard normal table

Given M = 500 T = 100 n -30 if clain is true u=500 To find P(* <490) we know that X follow Normal (ui X n Normal ( 500, 100 1

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