$11\mathrm{.}9$ A $12-$in$.$ fuli$-$depth asphalt pavement is placed on a subgrade with an effective roadbed resilient modulus of $10,000$ psi. Assuming a layer coefficient of $0\mathrm{.}44$ for the hot mix asphalt, a drop in PSI from $4\mathrm{.}2$ to $2\mathrm{.}5,$ an overall standard deviation of $0\mathrm{.}5,$ and a predicted ESAL of $3{10}^7,$ determine the reliability of the design by the AASHTO equation, and check the result by the AASHTO design chart. $[$Answer: $88\%]$