Question 2

Is there a statistically significant difference?

The Pima people of North America have one of the highest rates of type 2 diabetes in the world. It appears that a number of social and environmental factors have contributed to the incidence of diabetes for the Pima’s. The data set to be used for this question is found in the file called PIMA.csv (use the version provided in vUWS), which contains information for 500 females and consists of the following four features: 

• age in years

• diastolic blood pressure

• Body Mass Index (BMI)

• whether the individual as ever been pregnant

an extract of the dataset is shown below in Table 2.

The goal of this question is to determine whether women who have never been pregnant, are more likely to have a lower BMI.

(i) Using R code, determine the mean BMI for each group of women. Mention any other basic statistics you consider are relevant and briefly state why?

(ii) Generate code to produce two useful plots, relating to the two groups. Briefly interpret the plots and state why you chose those plots? Make the plots worthy of inclusion within a report.

(iii) Perform a hypothesis test for the above mentioned two groups. Make sure you clearly include the following: 

• The Null and Alternative Hypotheses used

• Any assumptions, or important details / parameters used

• Declare the results of the hypothesis test

• Briefly interpret the meaning of the hypothesis test result

• State whether the result was as expected