# x06.txt # # Reference: # # R J Freund and P D Minton, # Regression Methods, # Dekker, 1979, page 111. # # Helmut Spaeth, # Mathematical Algorithms for Linear Regression, # Academic Press, 1991, page 305, # ISBN 0-12-656460-4. # # Discussion: # # The length of a species of fish is to be represented as a function # of the age and water temperature. The fish are kept in tanks # at 25, 27, 29 and 31 degrees Celsius. After birth, a test specimen # is chosen at random every 14 days and its length measured. # # There are 44 rows of data. The data include: # # I, the index; # A1, the age of the fish; # A2, the water temperature in degrees Celsius; # B, the length of the fish. # # We seek a model of the form: # # B = A1 * X1 + A2 * X2 # 4 columns 44 rows Index Age of fish (days) Temperature of water (degrees Celsius) Length of fish 1 14 25 620 2 28 25 1315 3 41 25 2120 4 55 25 2600 5 69 25 3110 6 83 25 3535 7 97 25 3935 8 111 25 4465 9 125 25 4530 10 139 25 4570 11 153 25 4600 12 14 27 625 13 28 27 1215 14 41 27 2110 15 55 27 2805 16 69 27 3255 17 83 27 4015 18 97 27 4315 19 111 27 4495 20 125 27 4535 21 139 27 4600 22 153 27 4600 23 14 29 590 24 28 29 1305 25 41 29 2140 26 55 29 2890 27 69 29 3920 28 83 29 3920 29 97 29 4515 30 111 29 4520 31 125 29 4525 32 139 29 4565 33 153 29 4566 34 14 31 590 35 28 31 1205 36 41 31 1915 37 55 31 2140 38 69 31 2710 39 83 31 3020 40 97 31 3030 41 111 31 3040 42 125 31 3180 43 139 31 3257 44 153 31 3214