Question

The​ quality-control manager at a compact fluorescent light bulb​ (cfl) factory needs to determine whether the mean life of a large shipment of cfls is equal to 7 comma 454 hours. the population standard deviation is 1 comma 080 hours. a random sample of 81 light bulbs indicates a sample mean life of 7 comma 154 hours.

a. at the 0.05 level of​ significance, is there evidence that the mean life is different from 7 comma 454 hours question mark

Answer 1

Are there other options? BEcause the information you provided, you would NOT be able to say that the mean is different than 7,454 because the sample is within 1 standard deviation from the proposed mean.