I need answer asap

6. a) Milly wants to examine the relationship between walking distance and BMI in COPD patients. Whether she can go for: Calculate a correlation coefficient or Run a linear regression model or she can do both? Justify your answer b) Milly also wants to know if there is a relationship between walking distance and smoking status (with categories 'current' or 'ex-smokers'). Which of the correlation analysis should Milly calculate? Why? c) If the B coefficient had a 95% confidence interval that ranged from -5.74 to -0.47. What does this indicate? d) Milly decides to use the more detailed assessment of smoking status captured by the variable PackHistory (which records a person's pack years smoking, where pack years is defined as twenty cigarettes smoked every day for one year) to explore the relationship between walking distance and smoking status. Milly finds: MWT1best= a+B*PackHistory =442.2 -1.1*PackHistory and the corresponding 95% confidence interval for B ranges from -1.9 to -0.25. What does it mean? e) Milly decides to fit the multivariable model with age, FEV1 and smoking pack years as predictors. MWT1best= a+81*AGE+82*FEV1+ 83*PackHistory Milly is wondering whether this is a reasonable model to fit. Why should she wonder about the model? f) Milly has now fitted several models and she wants to pick a final model. What statistic(s) can help her make this decision? g) Milly has fitted the following 5 models. Using only the information in the table below, which model do you think Milly should take as her final one? Justify. Adjusted R2 Model 1 MWT1best = a + 3, * AGE 0.0433 Model 2 MWT1best = a+ B, *FEV1 0.2122 Model 3 MWT1best = a + B, * PackHistory 0.0540 Model 4 MWT1best = a + 3, * AGE + B, * FEV1 0.2394 Model 5 MWT1best = a + , * AGE + B, * FEV1 + By * PackHistory 0.2717