Seven different hardwood concentrations are being studied to determine their effect on the strength of the paper produced. However, the pilot plant can only produce three runs each day. As days may differ, the analyst uses the BIBD that follows. Analyze the data from this experiment (use ???? = 0.05)

and draw conclusions.

Hardwood Days Concentration (%) 1 2 3 4 2 114 4 126 120 6 137 117 8 141 129 149 10 145 150 12 120 14 136 Hardwood Days Concentration (%) 5 6 7 2 120 117 4 119 6 134 8

10 143 12 118 123 14 130 127