List $7$ great attributes of an active listener$4.$ The tabulation and network diagram below represent a retooling project for a manufacturing company. The retooling is necessary to qualify for funding from a multinational agency for expansion of the plant. The retooling project was originally scheduled for a later date but has to be brought forward and crashed to meet the funding application deadline. $[30]$

a$)$ Find the cost slope, maximum reduced time and the cost for the project for normal time. $[5]$

b$)$ Hence, crash the project to meet a deadline of $18$ days and determine the associated cost.