Solusi - Probabilitas kumulatif dalam distribusi normal standar

More than $$99,9\%$$ of the time, data with a standard normal distribution lies within plus or minus $$3,9$$ standard deviations of the mean.

The cumulative probability of the values up to $$-9$$ is $$0$$.
$$p\left(x<-9\right)=0$$
The cumulative probability that $$x<-9$$ is $$0\%$$