A metal alloy is used to make components for aircraft engines. Cracking is a potentially serious problem in the nal part, as it can lead to a non-recoverable failure. The objective of the experiment was to identify the key factors and possibly their interactions which have effects on cracks. Four factors were considered: pouring temperature (A), titanium content (B), heat temperature method (C), and the amount of grain rener used (D). A full factorial experiment was conducted and the response of interest was the length of crack (in mmX10'2). Each trial condition was replicated twice. The data are given in the Table below. Calculate the factorial effects, including main effects, two-way, three-way and four-way interaction effects. Which factorial effects are si - B_11ificant for the crack len- h