An axial load P $=12\mathrm{.}4$ kips is applied with an eccentricity e $=0\mathrm{.}5$d to the circular steel rod BC that is free at its top and fixed at its base B$.$ Knowing that the stock of rods available for use have diameters in increments if $18$

in$.$ from $1\mathrm{.}5$ in$.$ to $3$ in$.,$ determine the lightest rod that can be used if $\backslash$sigma all $=15$ ksi. Use E $=29\backslash$times $106$ psi.