For the total number of vessels owned by each country in Exercise 1.57, the following breakdown for two different categories (national flag or foreign flag) was obtained:

Number of vessels Total National Flag Foreign Flag Japan 909 3,001 3,910 China 4,569 2,300 6,869 Singapore 1,493 1,368 2,861 Hong Kong, China 883 807 1,690

a. Graphically depict the number of vessels by category with a component bar chart.

b. Graphically depict the number of vessels by category with a cluster bar chart.