a certain type of light bulb has an average life of 500 hours, with a standard deviation of 100 hours. the length of the life of the bulb can be closely approximated by a normal curve. an amusement park buys and installs 10,000 such bulbs. find the total number that can be expected to last for each period of time.

Question

anonymous · Answer

a. at least 500 hours
b. between 650 and 780 hours
c. less than 740 hours

dan815 · Answer

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