For the normal distribution, given,
[tex]\begin{gathered} \mu=110 \\ \sigma=20 \end{gathered}[/tex]Let use the z-score formula to find the zscore corresponding to the value x = 104.
[tex]\begin{gathered} z=\frac{x-\mu}{\sigma} \\ z=\frac{104-110}{20} \\ z=\frac{-6}{20} \\ z=-0.3 \end{gathered}[/tex]Thus, we need
[tex]P(z<-0.3)[/tex]Using a normal distribution table/calculator, we can figure out the answer.
[tex]P(z<-0.3)=0.38209[/tex]About 38.215% of 1040R tax forms will be completed in less than 104 minutes.
