1. Use the DDT data set which records measurements on 144 fish caught on the Tennessee river and its tributaries:

2. Plot the boxplot of the DDT variable using whiskers extending as far as 3 Interquartile ranges

3. Using the boxplot() function in R find the outliers: Hint: Use the list output from the function

4. Using the boxplot method find the possible outliers: Hint: setdiff() might be useful though not absolutely necessary

5. Use the z technique to find outliers -- what are they?

6. What deficiency do you see in the use of z to find outliers?

DDT data set:

RIVER	MILE	SPECIES	LENGTH	WEIGHT	DDT
FCM	5	CCATFISH	42.5	732	10
FCM	5	CCATFISH	44	795	16
FCM	5	CCATFISH	41.5	547	23
FCM	5	CCATFISH	39	465	21
FCM	5	CCATFISH	50.5	1252	50
FCM	5	CCATFISH	52	1255	150
LCM	3	CCATFISH	40.5	741	28
LCM	3	CCATFISH	48	1151	7.7
LCM	3	CCATFISH	48	1186	2
LCM	3	CCATFISH	43.5	754	19
LCM	3	CCATFISH	40.5	679	16
LCM	3	CCATFISH	47.5	985	5.4
SCM	1	CCATFISH	44.5	1133	2.6
SCM	1	CCATFISH	46	1139	3.1
SCM	1	CCATFISH	48	1186	3.5
SCM	1	CCATFISH	45	984	9.1
SCM	1	CCATFISH	43	965	7.8
SCM	1	CCATFISH	45	1084	4.1
TRM	275	CCATFISH	48	986	8.4
TRM	275	CCATFISH	45	1023	15
TRM	275	CCATFISH	49	1266	25
TRM	275	CCATFISH	50	1086	5.6
TRM	275	CCATFISH	46	1044	4.6
TRM	275	CCATFISH	52	1770	8.2
TRM	280	CCATFISH	48	1048	6.1
TRM	280	CCATFISH	51	1641	13
TRM	280	CCATFISH	48.5	1331	6
TRM	280	CCATFISH	51	1728	6.6
TRM	280	CCATFISH	44	917	5.5
TRM	280	CCATFISH	51	1398	11
TRM	280	SMBUFFALO	49	1763	4.5
TRM	280	SMBUFFALO	46	1459	4.2
TRM	280	SMBUFFALO	52	2302	3
TRM	280	SMBUFFALO	46	1614	2.3
TRM	280	SMBUFFALO	46	1444	2.5
TRM	280	SMBUFFALO	48	2006	6.8
TRM	285	CCATFISH	44	936	19
TRM	285	CCATFISH	42	1058	7.2
TRM	285	CCATFISH	42.5	800	6
TRM	285	CCATFISH	45.5	1087	10
TRM	285	CCATFISH	48	1329	12
TRM	285	CCATFISH	44	897	2.8
TRM	285	LMBASS	28.5	778	0.48
TRM	285	LMBASS	26	532	0.18
TRM	285	LMBASS	25.5	441	0.34
TRM	285	LMBASS	25	544	0.11
TRM	285	LMBASS	23	393	0.22
TRM	285	LMBASS	28	733	0.8
TRM	290	CCATFISH	41	961	8.7
TRM	290	CCATFISH	44	886	22
TRM	290	CCATFISH	41	678	13
TRM	290	CCATFISH	42	1011	3.5
TRM	290	CCATFISH	42.5	947	9.3
TRM	290	CCATFISH	44	989	21
TRM	290	SMBUFFALO	43.5	1291	3.4
TRM	290	SMBUFFALO	46.5	1186	13
TRM	290	SMBUFFALO	43	1293	5.6
TRM	290	SMBUFFALO	47	1709	12
TRM	290	SMBUFFALO	46	1425	21
TRM	290	SMBUFFALO	41	1176	8
TRM	295	CCATFISH	36	980	12
TRM	295	CCATFISH	47.5	1176	6
TRM	295	CCATFISH	41.5	989	4.7
TRM	295	CCATFISH	49.5	1084	31
TRM	295	CCATFISH	46	1115	5.2
TRM	295	CCATFISH	46.5	724	27
TRM	300	CCATFISH	36	847	18
TRM	300	CCATFISH	37	876	7.5
TRM	300	CCATFISH	35	844	3
TRM	300	CCATFISH	36	908	13
TRM	300	CCATFISH	48	1358	7.3
TRM	300	CCATFISH	49	1019	15
TRM	300	SMBUFFALO	35.5	1300	1.3
TRM	300	SMBUFFALO	46	1365	4.8
TRM	300	SMBUFFALO	45	1437	5.1
TRM	300	SMBUFFALO	44.5	1460	5.1
TRM	300	SMBUFFALO	49	1671	4
TRM	300	SMBUFFALO	47.5	1717	10
TRM	305	CCATFISH	35	613	12
TRM	305	CCATFISH	51	353	22
TRM	305	CCATFISH	42.5	909	10
TRM	305	CCATFISH	38	886	11
TRM	305	CCATFISH	41	890	17
TRM	305	CCATFISH	47	1031	9.7
TRM	310	CCATFISH	45	1083	12
TRM	310	CCATFISH	45.5	864	4.7
TRM	310	CCATFISH	45	886	6
TRM	310	CCATFISH	45	965	3.8
TRM	310	CCATFISH	39	537	17
TRM	310	CCATFISH	40.5	630	12
TRM	310	SMBUFFALO	46	1486	1.4
TRM	310	SMBUFFALO	47	1743	6.1
TRM	310	SMBUFFALO	48.5	2061	2.8
TRM	310	SMBUFFALO	48	1707	4.8
TRM	310	SMBUFFALO	38	862	5.7
TRM	310	SMBUFFALO	38.5	911	3.3
TRM	315	CCATFISH	29.5	476	3.3
TRM	315	CCATFISH	42	743	3.7
TRM	315	CCATFISH	47.5	1128	9.9
TRM	315	CCATFISH	43.5	848	6.8
TRM	315	CCATFISH	47.5	1091	13
TRM	315	CCATFISH	43.5	715	8.8
TRM	320	CCATFISH	47.5	983	57
TRM	320	CCATFISH	51.5	1251	96
TRM	320	CCATFISH	49.5	1255	360
TRM	320	CCATFISH	47	1152	130
TRM	320	CCATFISH	47.5	1085	13
TRM	320	CCATFISH	47	1118	61
TRM	320	SMBUFFALO	36	1285	12
TRM	320	SMBUFFALO	34.5	1178	33
TRM	320	SMBUFFALO	44.5	1492	48
TRM	320	SMBUFFALO	46	1524	10
TRM	320	SMBUFFALO	46	1473	44
TRM	320	SMBUFFALO	32.5	520	0.43
TRM	325	CCATFISH	46	863	1100
TRM	325	CCATFISH	40	549	9.4
TRM	325	CCATFISH	43.5	810	4.1
TRM	325	CCATFISH	46.5	908	2.8
TRM	325	CCATFISH	43	804	0.74
TRM	325	CCATFISH	47.5	1179	14
TRM	330	CCATFISH	32	556	22
TRM	330	CCATFISH	40.5	659	9.1
TRM	330	CCATFISH	51.5	1229	140
TRM	330	CCATFISH	48	1050	4.2
TRM	330	CCATFISH	47	952	12
TRM	330	CCATFISH	41	826	2
TRM	330	SMBUFFALO	33.5	599	0.3
TRM	330	SMBUFFALO	47	1704	1.2
TRM	340	CCATFISH	50	1207	7.1
TRM	340	CCATFISH	45	911	180
TRM	340	CCATFISH	49	1498	1.5
TRM	340	CCATFISH	49.5	1496	2.4
TRM	340	CCATFISH	50	1142	4.3
TRM	340	CCATFISH	45	879	3.9
TRM	340	SMBUFFALO	32.5	525	0.99
TRM	340	SMBUFFALO	38	806	0.45
TRM	340	SMBUFFALO	38.5	694	2.5
TRM	340	SMBUFFALO	36	643	0.25
TRM	345	LMBASS	26.5	514	0.58
TRM	345	LMBASS	23.5	358	2
TRM	345	LMBASS	30	856	2.2
TRM	345	LMBASS	29	793	7.4
TRM	345	LMBASS	17.5	173	0.35
TRM	345	LMBASS	36	1433	1.9