48 animals were exposed to 4 treatments and three poisons. The response is the (log) survival time

Time Trt Poison

0.31  1  1
0.45  1  1
0.46  1  1
0.43  1  1
0.82  2  1
1.10  2  1
0.88  2  1
0.72  2  1
0.43  3  1
0.45  3  1
0.63  3  1
0.76  3  1
0.45  4  1
0.71  4  1
0.66  4  1
0.62  4  1
0.36  1  2
0.29  1  2
0.40  1  2
0.23  1  2
0.92  2  2
0.61  2  2
0.49  2  2
1.24  2  2
0.44  3  2
0.35  3  2
0.31  3  2
0.40  3  2
0.56  4  2
1.02  4  2
0.71  4  2
0.38  4  2
0.22  1  3
0.21  1  3
0.18  1  3
0.23  1  3
0.30  2  3
0.37  2  3
0.38  2  3
0.29  2  3
0.23  3  3
0.25  3  3
0.24  3  3
0.22  3  3
0.30  4  3
0.36  4  3
0.31  4  3
0.33  4  3