Question

** Use R for the following analysis.

Use the BoneAcid.xlsx data to check what is causing the variation in the acid content in bones among 42 male skeletons from 2 cemeteries. The independent variables included are internment lengths, ages, depths, lime addition and contamination in soil.

Variables/Columns

Burial Site   (1 or 2)

Internment Time (Years)

Burial Depth (feet)   

LimeAdded (at internment) (1=Yes, 0=No)

Death_Age (Age of Person at the time of death)

Acid Level (g/100g of bone)

Contamination (In soil) (1=Yes, 0=No)  

1. Undertake appropriate basic data analytics to motivate the regression model Use dummy variables for each of Burial Site, LimeAdded, and Contamination (If required create the dummy-variables for each).

2. Do you suspect any multicollinearity problem could affect the regression coefficients?

3. Run a regression model of the Acid Level on all independent variables provided and interpret all regression coefficients.

4. Briefly describe what you need to do before conducting any hypothesis testing when you find evidence of heteroscedasticity in an OLS regression model? Test for heteroscedasticity to check for evidence of heteroscedasticity in part 3

5. Test the hypothesis that

i. Beta_InternmentTime < -0.00675

ii. Jointly Beta_BurialSite = Beta_BurialDepth =Beta_LimeAdded=0

6, What is the best model specification that would explain acid content in bones better?

Burial Site	InternmentTime	Baurial Depth	LimeAdded	Death_Age	Contamination	Acid Level
1	88.5	7	1	34	1	3.88
1	88.5	7	1	38	1	4
1	85.2	7	1	27	1	3.69
1	71.8	7.6	1	26	0	3.88
1	70.6	7.5	1	42	0	3.53
1	68	7	1	28	0	3.93
1	71.6	8	1	35	0	3.88
1	70.2	6	1	44	0	3.64
1	55.5	6	0	29	0	3.97
1	36.5	6.5	0	29	0	3.85
1	36.3	6.5	0	48	0	3.96
1	46.5	6.5	0	35	0	3.69
1	35.9	6.5	0	40	0	3.76
1	45.5	6.5	0	34	0	3.75
1	43	6.5	0	38	0	3.75
1	44.9	6.5	0	27	0	3.92
1	59.5	8	0	26	0	3.76
1	58.3	8	0	23	0	3.93
1	56.5	8	0	35	0	3.7
1	56.3	8	0	23	0	3.82
1	43	6.5	0	40	0	3.78
1	42.5	9	0	31	0	4
1	29	7.5	0	31	0	3.92
1	35.3	8.5	0	39	0	3.79
2	93.6	4	1	39	0	3.49
2	90	4	1	43	0	3.57
2	88	5.5	1	26	0	3.43
2	84.4	5	1	47	0	3.55
2	84	4.75	1	39	0	3.5
2	79.7	4.75	1	27	0	3.27
2	67.4	4.5	1	39	0	3.66
2	64.7	5	1	27	0	3.9
2	64.7	5.5	1	35	1	3.91
2	38.3	7	0	21	0	3.73
2	59.6	9.25	0	46	0	3.72
2	32	9	0	24	0	3.85
2	32.2	9	0	27	0	3.85
2	26.5	7	0	34	0	4.06
2	34.7	8.5	0	30	0	4.04
2	27.6	6	0	22	0	4
2	35.7	9	0	19	0	3.93
2	49.6	9	0	50	0	3.85

Answer 1