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 selectsUltra batteries and finds that they have a mean lifetime ofhours, with a standard deviation ofhours. 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? of the lifetimes lie between 690 hours and1062.

56%

75%

84%

89%

b) According to Chebyshev's theorem, at least? of the lifetimes lie between 597 hours and1155.

56%

75%

84%

89%

(c) Suppose that the distribution is bell-shaped. According to the empirical rule, approximately?

68%

75%

95%

99.7%

of the lifetimes lie between 690 hours and1062.

(d) Suppose that the distribution is bell-shaped. According to the empirical rule, approximately 68% of the lifetimes lie betweenhours ? and the hours ?