1. A survey was conducted among 100 adult men aged 30–40 years. The data on their body mass index (BMI) and serum triglyceride levels are summarized as histograms shown in Figure 2.14.

(a) Are histograms a proper choice for describing these data? Are there possible alternatives? How can you visualize the relationship between BMI and serum triglyceride levels? What are the advantages of graphic description in this sample?

(b) Can we replace the frequencies in the histograms with relative frequencies (%)?

What are the similarities and difference between frequencies and relative frequencies?

(c) Which statistics do you plan to use to describe the distribution of BMI and serum triglyceride levels? Justify your choices.

(d) What are the advantages of using descriptive statistics? What are the advantages of using both descriptive statistics and graphics?

(e) What are the roles of statistics in the description of central tendency and degree of dispersion? Is the joint use of these two types of statistics always necessary?