Is this correct? Summary statistics for dias: Group by: BMIcat BMIcat n Mean Var

ID: 3072561 • Letter: I

Question

Is this correct?

Summary statistics for dias:

Group by: BMIcat

BMIcat

Mean

Variance

Std. dev.

Std. err.

Median

Range

Min

Max

1: normal

37 (46.25%)

66.837838

105.91742

10.291619

1.6919317

2:overweight

30 (37.5%)

71.133333

102.6023

10.129279

1.8493449

73.5

3: obese

13 (16.25%)

78.384615

91.25641

9.5528221

2.6494761

102

This data has been reached using the five number summary produced by StatCrunch to identify the relationship between BMI category and diastolic blood pressure. When evaluated it is shown that BMI category is a significant predictor of high diastolic BP. Participants of normal weight were less likely to have high diastolic BP than those who were in overweight category.

Outliers: In this dataset there are two suspected outliers. The max diastolic BP for those in the obese category is 102, which is considered a suspected outlier using the 1.5(IQR) criterion (83+1.5(11)=99.5). The minimum diastolic BP for those in the overweight BMI category is 41, which is also considered a suspected outlier using the 1.5(IQR) criterion (65-1.5(14)=44). Those considered of normal do not have any suspected outliers.

Center: The median diastolic blood pressure in those of normal BMI (65) is less than the median of the other two distributions overweight (73.5) and obese (79).

Spread: The obese BMI category has the smallest variation in diastolic BP (range=36, IQR= 11) 50% range from 72 mmHg to 83 mmHg. Larger variation in diastolic blood pressure are found in those with normal BMI (range=41, IQR=12) where 50% of participants range from 61 mmHg to 73 mmHg. Those in the overweight (range= 46, IQR=14) BMI categories where 50% range from 65 mmHg to 83 mmHg.

This summary also provides the distribution of subjects in the different categories of BMI and Diastolic BP. Maximum numbers of participants were in the normal BMI category (46.25%) followed by those in overweight category (37.5%). The lowest number of participants were found in the obese category (16.25%).

b. Include graphical presentation of this relationship.

c. Describe the graph from 5b.

By examining the three side-by-side boxplots and the numerical summaries, we see at once that BMI category obese, as a group has a higher diastolic blood pressure than those considered normal and overweight.