What is the minimum completion time $($in days$)$ of the project?

The following four activities were identified as being on the critical path. How much will it cost the project manager to reduce the length of the project to $38$ weeks?

$\backslash$table$[[,\backslash$table$[[$Normal Time$],[($weeks$)]],$Normal Cost,$\backslash$table$[[$Crash Time$],[($weeks$)]],$Crash Cost$],[$Activity$,12,$$$4,000,8,$$$7,600$