GIVEN
The following values are given:
[tex]\begin{gathered} \mu=10.3 \\ \sigma=3.8 \end{gathered}[/tex]SOLUTION
The z-score for the x values 9 and 14 can be calculated using the formula:
[tex]z=\frac{x-\mu}{\sigma}[/tex]For x = 9:
[tex]\begin{gathered} z=\frac{9-10.3}{3.8} \\ z=-0.34 \end{gathered}[/tex]For x = 14:
[tex]\begin{gathered} z=\frac{14-10.3}{3.8} \\ z=0.97 \end{gathered}[/tex]The probability can be calculated as follows:
[tex]P(9\le x\le14)=Pr(-0.34The region that represents the solution is shown below:Therefore, the probability is given to be:
[tex]P(9\le x\le14)=0.4671[/tex]The probability is 0.4671.