## Elementary Statistics (12th Edition)

About 99.73% of the area is between $z=-3$ and $z=3$.
These steps are for a TI-83/84 calculator. 1. Press "2nd" "VARS" to get to the DISTR menu. 2. Select "normalcdf" 3. Enter the z-scores, which are $z=-3$ and $z=3$, as $(-3,3)$. 4. Press "enter" Your result should be $0.9973$. This correlates to 99.73%, which means that 99.73% of the area is within 3 standard deviations of the mean.