Refer to the continuous T$-$beam shown below. Image $($a$)$ shows the cross$-$section of the continuous T$-$beam. Image $($b$)$ shows the span of the T$-$beam.$($a$)$ Beam section and distance to adjacent beams

$$ Compute the effective flange width for the T$-$beam in the middle of image $($a$).$ You should only use the clear span, so you need to subtract out half of the column width $(18)$ on each end to get the clear span and use that value for l$.$

$$ At midspan, there are two layers of tension rebar: $(3)$ #$8$s in the bottom layer and $(2)$ #$7$s in the layer above. Assume minimum rebar spacing is satisfied. If the concrete has a compressive strength $($fc$)$ of $5,000$ psi, the rebar is Gr$.60,$ and there is a $1\mathrm{.}5$ cover, what is the design moment capacity $(\backslash$Phi Mn$)$ for the T$-$beam in the middle of image $($a$)$ at midspan $($i$.$e$.$ where there is positive bending only and no compression reinforcement$)?$