A replicated fractional factorial design is used to investigate the effect of four factors on the free height of leaf springs used in an automotive application. The factors are (A) furnace temperature, (B) heating time, (C) transfer time, and (D) hold down time. There are 3 observations at each setting. Write out the alias structure for this design. What is the resolution of this design? Analyze the data. What factors influence the mean free height? The data set appears in the file "Springs.xlsx". ABCD Height -1 -1 -1 -1 8.56 8.56 8.62 1-1 -1 1 9.30 9.36 8.76 1-1 1 8.00 8.12 8.00 -1 1 1-1 -1 8.18 8.12 8.50 -1 -1 1 1 8.08 9.00 8.76 1-1 1 -1 -1 1 1 -1 1 1 1 1 -1 8.38 9.18 9.12 8.12 8.04 7.88 8.12 8.62 8.38 -1 -1 -1 8.00 7.50 7.24 1-1-1 1 8.76 8.76 7.88 -1 1-1 1 8.00 8.12 8.00 1 1-1 -1 8.26 8.50 8.12 -1 -1 1-1 111 -1 1 1 1 7.64 7.88 7.88 1-1 8.12 8.38 8.24 1 -1 7.36 7.36 7.50 1 1 1 8.62 8.00 8.18