$3-5.$ A $5-$foot diameter circular footing for a new highway light pole is being installed at a depth of $6$ feet below the existing ground surface. The groundwater table is at great depth. Determine the allowable bearing pressure $($considering a factor of safety of $3\mathrm{.}0)$ using the following parameters:

$=120l\frac{b}{f}{t}^3,c^{\text{'}}=100l\frac{b}{f}{t}^2,$ and ${}^{\text{'}}=28.$