Consider the melanoma data (melanoma.csv, melanoma.txt). This data is properly analyzed with what is called a proportional hazards model, but let's use the tools we have: ignore the 'time' variable and assume that the 'status' variable simply reflects the status of the individual at a follow-up time, whenever that was. Let's say we are interested in the relationship between features of a malignant melanoma (its size, operationalized as its thickness, and whether an ulcer was present or not) and whether or not the patient was alive at the time of follow-up. 1. What type of regression model is most appropriate for this question, and why? 2. Do you need to do any data management in order to fit your model? If so, what do you choose to do, and why? 3. What predictor variables will you use in your model? Why did you choose these variables? 4. Estimate your model, present the results in a table, and interpret the results in words (a paragraph or so).

	time	status	sex	age	year	thickness	ulcer
1	10	3	1	76	1972	6.76	1
2	30	3	1	56	1968	0.65	0
3	35	2	1	41	1977	1.34	0
4	99	3	0	71	1968	2.9	0
5	185	1	1	52	1965	12.08	1
6	204	1	1	28	1971	4.84	1
7	210	1	1	77	1972	5.16	1
8	232	3	0	60	1974	3.22	1
9	232	1	1	49	1968	12.88	1
10	279	1	0	68	1971	7.41	1
11	295	1	0	53	1969	4.19	1
12	355	3	0	64	1972	0.16	1
13	386	1	0	68	1965	3.87	1
14	426	1	1	63	1970	4.84	1
15	469	1	0	14	1969	2.42	1
16	493	3	1	72	1971	12.56	1
17	529	1	1	46	1971	5.8	1
18	621	1	1	72	1972	7.06	1
19	629	1	1	95	1968	5.48	1
20	659	1	1	54	1972	7.73	1
21	667	1	0	89	1968	13.85	1
22	718	1	1	25	1967	2.34	1
23	752	1	1	37	1973	4.19	1
24	779	1	1	43	1967	4.04	1
25	793	1	1	68	1970	4.84	1
26	817	1	0	67	1966	0.32	0
27	826	3	0	86	1965	8.54	1
28	833	1	0	56	1971	2.58	1
29	858	1	0	16	1967	3.56	0
30	869	1	0	42	1965	3.54	0
31	872	1	0	65	1968	0.97	0
32	967	1	1	52	1970	4.83	1
33	977	1	1	58	1967	1.62	1
34	982	1	0	60	1970	6.44	1
35	1041	1	1	68	1967	14.66	0
36	1055	1	0	75	1967	2.58	1
37	1062	1	1	19	1966	3.87	1
38	1075	1	1	66	1971	3.54	1
39	1156	1	0	56	1970	1.34	1
40	1228	1	1	46	1973	2.24	1
41	1252	1	0	58	1971	3.87	1
42	1271	1	0	74	1971	3.54	1
43	1312	1	0	65	1970	17.42	1
44	1427	3	1	64	1972	1.29	0
45	1435	1	1	27	1969	3.22	0
46	1499	2	1	73	1973	1.29	0
47	1506	1	1	56	1970	4.51	1
48	1508	2	1	63	1973	8.38	1
49	1510	2	0	69	1973	1.94	0
50	1512	2	0	77	1973	0.16	0
51	1516	1	1	80	1968	2.58	1
52	1525	3	0	76	1970	1.29	1
53	1542	2	0	65	1973	0.16	0
54	1548	1	0	61	1972	1.62	0
55	1557	2	0	26	1973	1.29	0
56	1560	1	0	57	1973	2.1	0
57	1563	2	0	45	1973	0.32	0
58	1584	1	1	31	1970	0.81	0
59	1605	2	0	36	1973	1.13	0
60	1621	1	0	46	1972	5.16	1
61	1627	2	0	43	1973	1.62	0
62	1634	2	0	68	1973	1.37	0
63	1641	2	1	57	1973	0.24	0
64	1641	2	0	57	1973	0.81	0
65	1648	2	0	55	1973	1.29	0
66	1652	2	0	58	1973	1.29	0
67	1654	2	1	20	1973	0.97	0
68	1654	2	0	67	1973	1.13	0
69	1667	1	0	44	1971	5.8	1
70	1678	2	0	59	1973	1.29	0
71	1685	2	0	32	1973	0.48	0
72	1690	1	1	83	1971	1.62	0
73	1710	2	0	55	1973	2.26	0
74	1710	2	1	15	1973	0.58	0
75	1726	1	0	58	1970	0.97	1
76	1745	2	0	47	1973	2.58	1
77	1762	2	0	54	1973	0.81	0
78	1779	2	1	55	1973	3.54	1
79	1787	2	1	38	1973	0.97	0
80	1787	2	0	41	1973	1.78	1
81	1793	2	0	56	1973	1.94	0
82	1804	2	0	48	1973	1.29	0
83	1812	2	1	44	1973	3.22	1
84	1836	2	0	70	1972	1.53	0
85	1839	2	0	40	1972	1.29	0
86	1839	2	1	53	1972	1.62	1
87	1854	2	0	65	1972	1.62	1
88	1856	2	1	54	1972	0.32	0
89	1860	3	1	71	1969	4.84	1
90	1864	2	0	49	1972	1.29	0
91	1899	2	0	55	1972	0.97	0
92	1914	2	0	69	1972	3.06	0
93	1919	2	1	83	1972	3.54	0
94	1920	2	1	60	1972	1.62	1
95	1927	2	1	40	1972	2.58	1
96	1933	1	0	77	1972	1.94	0
97	1942	2	0	35	1972	0.81	0
98	1955	2	0	46	1972	7.73	1
99	1956	2	0	34	1972	0.97	0
100	1958	2	0	69	1972	12.88	0
101	1963	2	0	60	1972	2.58	0
102	1970	2	1	84	1972	4.09	1
103	2005	2	0	66	1972	0.64	0
104	2007	2	1	56	1972	0.97	0
105	2011	2	0	75	1972	3.22	1
106	2024	2	0	36	1972	1.62	0
107	2028	2	1	52	1972	3.87	1
108	2038	2	0	58	1972	0.32	1
109	2056	2	0	39	1972	0.32	0
110	2059	2	1	68	1972	3.22	1
111	2061	1	1	71	1968	2.26	0
112	2062	1	0	52	1965	3.06	0
113	2075	2	1	55	1972	2.58	1
114	2085	3	0	66	1970	0.65	0
115	2102	2	1	35	1972	1.13	0
116	2103	1	1	44	1966	0.81	0
117	2104	2	0	72	1972	0.97	0
118	2108	1	0	58	1969	1.76	1
119	2112	2	0	54	1972	1.94	1
120	2150	2	0	33	1972	0.65	0
121	2156	2	0	45	1972	0.97	0
122	2165	2	1	62	1972	5.64	0
123	2209	2	0	72	1971	9.66	0
124	2227	2	0	51	1971	0.1	0
125	2227	2	1	77	1971	5.48	1
126	2256	1	0	43	1971	2.26	1
127	2264	2	0	65	1971	4.83	1
128	2339	2	0	63	1971	0.97	0
129	2361	2	1	60	1971	0.97	0
130	2387	2	0	50	1971	5.16	1
131	2388	1	1	40	1966	0.81	0
132	2403	2	0	67	1971	2.9	1
133	2426	2	0	69	1971	3.87	0
134	2426	2	0	74	1971	1.94	1
135	2431	2	0	49	1971	0.16	0
136	2460	2	0	47	1971	0.64	0
137	2467	1	0	42	1965	2.26	1
138	2492	2	0	54	1971	1.45	0
139	2493	2	1	72	1971	4.82	1
140	2521	2	0	45	1971	1.29	1
141	2542	2	1	67	1971	7.89	1
142	2559	2	0	48	1970	0.81	1
143	2565	1	1	34	1970	3.54	1
144	2570	2	0	44	1970	1.29	0
145	2660	2	0	31	1970	0.64	0
146	2666	2	0	42	1970	3.22	1
147	2676	2	0	24	1970	1.45	1
148	2738	2	0	58	1970	0.48	0
149	2782	1	1	78	1969	1.94	0
150	2787	2	1	62	1970	0.16	0
151	2984	2	1	70	1969	0.16	0
152	3032	2	0	35	1969	1.29	0
153	3040	2	0	61	1969	1.94	0
154	3042	1	0	54	1967	3.54	1
155	3067	2	0	29	1969	0.81	0
156	3079	2	1	64	1969	0.65	0
157	3101	2	1	47	1969	7.09	0
158	3144	2	1	62	1969	0.16	0
159	3152	2	0	32	1969	1.62	0
160	3154	3	1	49	1969	1.62	0
161	3180	2	0	25	1969	1.29	0
162	3182	3	1	49	1966	6.12	0
163	3185	2	0	64	1969	0.48	0
164	3199	2	0	36	1969	0.64	0
165	3228	2	0	58	1969	3.22	1
166	3229	2	0	37	1969	1.94	0
167	3278	2	1	54	1969	2.58	0
168	3297	2	0	61	1968	2.58	1
169	3328	2	1	31	1968	0.81	0
170	3330	2	1	61	1968	0.81	1
171	3338	1	0	60	1967	3.22	1
172	3383	2	0	43	1968	0.32	0
173	3384	2	0	68	1968	3.22	1
174	3385	2	0	4	1968	2.74	0
175	3388	2	1	60	1968	4.84	1
176	3402	2	1	50	1968	1.62	0
177	3441	2	0	20	1968	0.65	0
178	3458	3	0	54	1967	1.45	0
179	3459	2	0	29	1968	0.65	0
180	3459	2	1	56	1968	1.29	1
181	3476	2	0	60	1968	1.62	0
182	3523	2	0	46	1968	3.54	0
183	3667	2	0	42	1967	3.22	0
184	3695	2	0	34	1967	0.65	0
185	3695	2	0	56	1967	1.03	0
186	3776	2	1	12	1967	7.09	1
187	3776	2	0	21	1967	1.29	1
188	3830	2	1	46	1967	0.65	0
189	3856	2	0	49	1967	1.78	0
190	3872	2	0	35	1967	12.24	1
191	3909	2	1	42	1967	8.06	1
192	3968	2	0	47	1967	0.81	0
193	4001	2	0	69	1967	2.1	0
194	4103	2	0	52	1966	3.87	0
195	4119	2	1	52	1966	0.65	0
196	4124	2	0	30	1966	1.94	1
197	4207	2	1	22	1966	0.65	0
198	4310	2	1	55	1966	2.1	0
199	4390	2	0	26	1965	1.94	1
200	4479	2	0	19	1965	1.13	1
201	4492	2	1	29	1965	7.06	1
202	4668	2	0	40	1965	6.12	0
203	4688	2	0	42	1965	0.48	0
204	4926	2	0	50	1964	2.26	0
205	5565	2	0	41	1962	2.9	0