Use the data in NutritionStudy to assess the conditions for doing inference on a regression model to predict a person’s cholesterol level, Cholesterol, from the daily grams of fat, Fat. Explain your reasoning, using each of the three relevant graphs.

Data in NutritionStudy 

Data on 315 patients undergoing elective surgery from a cross-sectional study to investigate the relationship between personal characteristics and dietary factors, and plasma concentrations of retinol, beta-carotene and other carotenoids. Study subjects were patients who had an elective surgical procedure during a three-year period to biopsy or remove a lesion of the lung, colon, breast, skin, ovary or uterus that was found to be non-cancerous.
ID ..................ID number for each subject in this sample
Age ................Subject’s age (in years)
Smoke ..........Does the subject smoke: Yes or No
Quetelet .......Weight/(Height2)
Vitamin ..........Vitamin use coded as: 1 = Regularly, 2 = Occasionally, or 3 = No
Calories .........Number of calories consumed per day
Fat .................Grams of fat consumed per day
Fiber .............Grams of fiber consumed per day
Alcohol ..........Number of alcoholic drinks consumed per week
Cholesterol ....Cholesterol consumed (mg per day)
BetaDiet .........Dietary beta-carotene consumed (mcg per day)
RetinolDiet ......Dietary retinol consumed (mcg per day)
BetaPlasma .....Concentration of beta-carotene (ng/ml) in the blood
RetinolPlasma ..Concentration of retinol (ng/ml) in the blood
Gender ..............Female or Male
VitaminUse .......Coded as No, Occasional, or Regular
PriorSmoke ......Smoking status coded as: 1 = Never, 2 = Former, or 3 = Current