Table 5.19 refers to a sample of subjects randomly selected for an Italian study on the relation between income and whether one possesses a travel credit card. At each level of annual income in millions of lira, the table indicates the number of subjects sampled and the number possessing at least one travel credit card. Analyze these data.

Table 5.19:

Income Number Income Number Income Number Credit (millions Cards of lira) Credit (millions Cases Cards of lira) (millions of lira) of of of Credit Cases Cases Cards 24 39 65 1 27 40 68 3 3 28 5 2 41 2 70 5 3 29 3 42 2 79 30 45 80 31 5 48 84 32 49 94 33 50 10 120 6. 34 52 130 1 35 59 1 38 60 5 2