221k views
1 vote
The Bespan of a laptop battery is normally distributed. If the meanifespan of a batteryis 4 years with a standard deviation of 1.6 years what is the probability that the nextlaptop battery you purchase will last between 3.5 and 5.5 years!15.21%84.79%55.19%44.81%

1 Answer

3 votes

Formula


\begin{gathered} Z=\text{ }(x-\mu)/(\sigma) \\ \text{Where} \\ Z=standardscore \\ x=observedvalue \\ \mu=meanofthesample \\ \sigma=standarddeviationofthesample \\ Z=\text{ }(3.5-4)/(1.6) \\ Z=-0.3125 \\ \\ \\ Z=\text{ }(5.5-4)/(1.6) \\ Z=0.9375 \end{gathered}

Z=standard score

x=observed value

u=mean of the sample

standard deviation of the sample

User Bhell
by
4.8k points