BIG Corporation produces just about everything but is currently interested in the lifetimes of its batteries, hoping to obtain its share of a market boosted by the popularity of portable CD and MP3 players. To investigate its new line of Ultra batteries, BIG randomly selects1000Ultra batteries and finds that they have a mean lifetime of814hours, with a standard deviation of84hours. Suppose that this mean and standard deviation apply to the population of all Ultra batteries. Complete the following statements about the distribution of lifetimes of all Ultra batteries.

(a) According to Chebyshev's theorem, at least 84% of the lifetimes lie between hoursand hours. (Round your answer to the nearest integer.) (b) According to Chebyshev's theorem, at least?56%75%84%89%of the lifetimes lie between 646 hours and 982 hours. (c) Suppose that the distribution is bell-shaped. According to the empirical rule, approximately?68%75%95%99.7%of the lifetimes lie between 646 hours and 982 hours. (d) Suppose that the distribution is bell-shaped. According to the empirical rule, approximately 99.7% of the lifetimes lie between hoursand hours.

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