$[15$ points$]$ Developer ABC is preparing for an upcoming project and recognizes the utmost importance of understanding the site's soil conditions. To assess soil permeability, a pumping test was conducted within a $25-$meter$-$thick soil bed. This test provided invaluable insights into the site's hydrogeological features. Gravelly layers were found within the first $2$ m $,$ and the initial groundwater level was located at a depth of $3\mathrm{.}5$ m from the ground level. Throughout the test, a pumping rate of $3\mathrm{.}73m^3$ in every five minutes was consistently maintained. Significant observations were made from wells positioned at distances of $18$ m and $27$ m from the edge of a $40-$meter$-$diameter pumping well, indicating drawdowns of $2\mathrm{.}1$ m and $1\mathrm{.}8$ m $,$ respectively.

a$.$ Determine the hydraulic conductivity, in $c\frac{m}{s}.$

b$.$ Determine the radius of influence $($in m $)$ and round your answer to the nearest whole number.

c$.$ Determine the maximum possible drawdown, in m $($assumed it will occur at the well face; any of the observation can be used as reference$).$