The empirical rule states that 99.7% of the data observed following a normal distribution lies within 3 standard deviations of the mean.
Given data:
Mean: 39oz
Standard deviation: 3oz
Multiply the standard deviation by 3:
![3\sigma=3(3)=9](https://img.qammunity.org/2023/formulas/mathematics/college/q4xzfdh58g5xvbqhv7nes9jv9gfcflqd57.png)
Add and subtract the result above to the mean to get the interval of 99.7% of the data;
![\begin{gathered} 39-9=30 \\ 39+9=48 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/8on4ws5l1d49f0hgab5qwmf8o4du7h6vhm.png)
Then, the 97.7% of the widget weights lie between 30 ounces and 48 ounces