A manufacturer reports that its light bulbs have an average life of 1,000 hours with a standard deviation of 32 hours.

A manufacturer reports that its light bulbs have an average life of 1,000 hours with a standard deviation of 32 hours. A retailer checks a random sample of 64 bulbs taken from the last order delivered. Find the minimum value of average duration that would accept the goods delivered if the level of significance is 0.05