Explore IDNLearn.com's extensive Q&A database and find the answers you need. Our experts provide prompt and accurate answers to help you make informed decisions on any topic.

An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with mean equal to 800 hours and a standard deviations of 40 hours. Find the probability that, a random sample of 16 bulbs will have an average life of i). Less that 775 hours. Ii) between 775 and 825 hours.