The Flashlight Batteries Produced by One of the Northern Manufacturers

Essay

The flashlight batteries produced by one of the northern manufacturers are known to have an average life of 60 hours with a standard deviation of 4 hours.Use Chebyshev's theorem to answer the following questions.
a.At least what percentage of flashlights will have a life of 54 to 66 hours?
b.At least what percentage of the batteries will have a life of 52 to 68 hours?
c.Determine an interval for the batteries' lives that will be true for at least 80% of the batteries.(Hint: First compute the Z-score. )