Case Study 1: COVID in Italy and China The following figures were obtained from a study' investigating the death rate among the COVID-19 patients (Case fatality rate) in Italy and China during the early COVID stages. Observe that for all age groups, death rates among Covid-19 patients in Italy are lower than those in China, but the overall death rate among the Covid-19 patients in Italy is higher than that in China. Fig 1: Death rate among Govid-19 patients by ape group Fig. 2 Proportion of Covid: 10 patients broken down by age group 20 15 Country Rates (in percentage) China toly 4.2 645- 49 Age Group 1, Let us designate Covid-19 patients aged 70 years and above as "Old", and all other Covid-19 patients as "Young". Let "D" represent death from Covid-19. a. What proportion of patients in Italy are old? How about China? Which country, Italy or China, is positively associated with old patients? b. In Italy, what is the death rate amongst the old patients, rate(D| Old)? Give your answers to 2 decimal places. c. From Fig 1, the overall death rate in Italy is 4.2. Using the basic rule of rates, what must be the possible range of the death rate amongst the young patients in Italy? Is there an association between age and death among Covid-19 patients in Italy? d. Repeat parts (b) and (c) for China. e. Let's assume the following rough estimates from Fig 1: In Italy, rate(D | Young) = 0.621%. In China, rate(D| Young) = 1.17%. Using the information from Q1(a) to (d), explain how it is possible for the overall death rate in Italy to be higher than that in China, despite Italy having a lower death rate in China for every age group, as shown in Fig 1. Hint: You may use the following table to help you: Italy China rate(D | Old) rate(D | Young) rate(D) rate(old)