A chemical Engineer wants to fit a straight line to the data found observing the tensile strength, Y, of 10 test pieces of plastic that have undergone baking (at a uniform temperature) for X minutes, where 10 values of X were preselected. The data (in coded units) is given below. Find, assuming n=E(Y l X) = B0 + B1X1 the least squares estimates of B0 and B1, and hence the least squares estimates of n. Construct 95% confidence intervals for B0 , B B1, and n0 = B0 + B1x0
| X |
23 |
35 |
45 |
65 |
75 |
95 |
105 |
125 |
155 |
185 |
| Y |
2 |
9.8 |
9.2 |
26.2 |
17.1 |
24.8 |
43 |
55.3 |
38.4 |
63.3 |