SOLUTION: 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 po

Algebra ->  Probability-and-statistics -> SOLUTION: 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 po      Log On


   

Question 401552: 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 selects 1000 Ultra batteries and finds that they have a mean lifetime of 853 hours, with a standard deviation of 100 hours. 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. Accourding to Chebyshev’s theorem, at least 8/9 (about 89%) of the lifetimes lie between ___hours and ____ hours.
b. Accourding to Chebyshev’s theorem, at least ___% of the lifetimes lie between 653 hrs and 1053 hrs.
c. Suppose that the distribution is bell shapped. According to the empirical rule, approx ____% pf the lifetimes lie between 653 hrs and 1053 hrs.
d. Suppose that the distribution is bell shapped. According to the empirical rule, approx 68% of the lifetimes lie between ___hrs and ____hrs.

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
a. 553 and 1153.(Corresponds to 3 SD's on both sides of the mean.)
b. %283%2F4%29%2A100% = 75%. (Corresponding to 2 SD's on both sides of the mean.)
c. 95% according to the 68 - 95 - 99.7 (empirical) rule. (Corresponding to 2 SD's on both sides of the mean.)
d. 753 and 953 (Corresponding to 1 SD on both sides of the mean.)