The quality-control manager at a light bulb factory needs to determine whether the mean life of a large shipment of light bulbs is equal to 375 hours. The population standard deviation is 100 hours. A random sample of 64 light bulbs indicates a sample mean life of 350 hours.

i. At the 0.05 level of significance, is there evidence that the mean life is different from 375 hours?

ii. Compute the p-value and interpret its meaning.

iii. Construct a 95% confidence interval estimate of the population mean life of the light bulbs.

iv. Compare the results of (i) and (ii). What conclusions do you reach?