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:
[tex]3\sigma=3(3)=9[/tex]Add and subtract the result above to the mean to get the interval of 99.7% of the data;
[tex]\begin{gathered} 39-9=30 \\ 39+9=48 \end{gathered}[/tex]Then, the 97.7% of the widget weights lie between 30 ounces and 48 ounces