Case Study 1: Systolic Blood Pressure and Cholesterol

Description

Total blood cholesterol and systolic blood pressure were measured in a group of 90 male (coded as 1) and female (coded as 2) adults. Each individual's smoking status (smoking, coded as 1 or non-smoking, coded as 0) was also recorded. The aim of this assignment is to examine the relationships between these variables.

Part 1: Describing and summarising the data

In this part of the assignment you will examine the dataset provided and present graphical and tabular summaries

1. For each of the four variables (sex, smoking status, systolic blood pressure and total blood cholesterol) identify the data type and exhibit the data graphically using an appropriate plot.

2. Summarise graphically the total blood cholesterol data for males and for females.

3. Summarise graphically the blood pressure data for smokers and for non-smokers.

4. Create a 2x2 table by sex and smoking status, showing the number of males and females that smoke and don't smoke.

Part 2: Drawing inferences

In this section you will use the data to test three hypotheses, using appropriate statistical techniques. In each case you should explain your reasoning.

5. Test the hypothesis that equal proportions of males and females smoke.

6. Determine whether there is a statistically significant difference in systolic blood pressure between smokers and non-smokers.

7. Determine whether there is there a statistically significant difference in total blood cholesterol between males and females.

Part 3: Identifying relationships

In this final section you will investigate qualitatively and quantitatively the relationship between systolic blood pressure and total blood cholesterol

8. Use an appropriate plot to investigate whether there is a suggestive relationship between systolic blood pressure and total blood cholesterol. If so, what sort of relationship might this be?

9. (a) Carry out a regression analysis with blood pressure as the dependent variable and total blood cholesterol as the independent variable. You should present the output and diagnostic plots in your report.

(b) From your output determine the expected change in systolic blood pressure for a one-unit change in the total blood cholesterol.

(c) Is this expected change statistically significantly different from zero? State which test you used to determine this.

Attachment:- Data.txt