A $15-$inch deep aggregate coarse$-$grained subbase layer of a flexible pavement has a modulus of resilience $($Mr$)$ of $300$ psi for the following conditions: number of road repetition: $2\mathrm{.}5$x$105,$ intercept strain determined from lab tests: $25$x$10-6,$ resilient strain imposed in lab tests: $70$x$10-6,$ average vertical resilient$/$elastic strain in the layer: $35$x$10-6,$ and water content: $12\%.$ Determine the following: $(1)$ the expected plastic deformation or rutting in the layer, and $(2)$ the standard error in computing the plastic deformation in part $(1).$