Question

A company installs 5000 light bulbs, each with an average life of 500 hours, standard deviation of 100 hours, and distribution approximated by a normal curve. Find the percentage of bulbs that can be expected to last the period of time.Less than 690 hours. . A. 97.06%. . B. 47.14%. . C. 97.1%. . D. 97.2%

Answer 1

The company installs 5000 light bulbs with an average of 500 hours for each bulb. The standard deviation of 100 hours and distribution approximated by a normal curve. The percentage of bulbs that can be expected to last the period of time of less than 690 hours is 97.1%. This will make the answer to be C.