(Solved): Find the center of the area of concrete area and \( \beta_{1}\left(\mathrm{fc}^{\prime}=6000 \mathr ...

Find the center of the area of concrete area and \( \beta_{1}\left(\mathrm{fc}^{\prime}=6000 \mathrm{psi}\right) \) \[ \begin{array}{l} \bar{y}=\frac{\sum y_{i} A_{i}}{\sum A_{i}} \\ a=\beta_{1} c \\ \beta_{1}=0.85 \text { for } f_{c} \leq 4000 p s i \\ \beta_{1}=0.85-0.05 \%\left[\frac{f_{c}-4000}{4000}\right] \geq 0.65 \end{array} \]