Question

Can someone show me how to do a test for lack of fit for the following data?

Please show all work by hand and not by computer for an up vote. Thanks.

y	x4	x7	x9
29.5	1.5	4	0
27.9	1.175	3	0
25.9	1.232	3	0
29.9	1.121	3	0
29.9	0.988	3	0
30.9	1.24	3	1
28.9	1.501	3	0
35.9	1.225	3	0
31.5	1.552	3	0
31	0.975	2	0
30.9	1.121	3	0
30	1.02	2	1
36.9	1.664	4	0
41.9	1.488	3	1
40.5	1.376	3	0
43.9	1.5	3	0
37.5	1.256	3	1
37.9	1.69	3	0
44.5	1.82	4	1
37.9	1.652	3	0
38.9	1.777	4	1
36.9	1.504	3	0
45.8	1.831	4	0
25.9	0.998	4	0

Answer 1