Problem $4$: A borehole shear test resulted in the following data.

Normal Stress

psi $($kPa$)$

Shear Stress

psi $($kPa$)$

$5\mathrm{.}5(37\mathrm{.}9)4(27\mathrm{.}6)$

$12(82\mathrm{.}7)4\mathrm{.}6(31\mathrm{.}7)$

$17\mathrm{.}7(122)11\mathrm{.}6(79\mathrm{.}9)$

$24(165)14\mathrm{.}7(101\mathrm{.}3)$

Estimate the cohesion and friction angle of the soil.