using the pdf as refrence Solve the following question

A series of $4-$m anchor walls spaced at $5$ m$,$ are used to restrain the top of a steel sheet

pile bulkhead, is to resist a force of $75$ kN$/$m of bulkhead. The top of the anchor wall is $2$ m

below the ground surface $.$ Factors of safety of $1\mathrm{.}4$ for tie force and $2\mathrm{.}1$ for net passive

resistance are considered. The anchor is embedded in sand soil whose angle of internal

friction is $29\backslash$deg and unit weight of $17\mathrm{.}5$ kN$/$m$^3.($i$)$ How high should the wall be$?,$ and $($ii$)$ How far

behind the bulkhead should it be placed?