The following data shows the number of students in different streams in a school: 
Which type of graph is best suited to represent this data?
To select the optimal graph for illustrating student counts across distinct school streams, analyze graph type attributes:
Considering the data comprises discrete categories (school streams) and the objective is to compare student numbers within them, a Bar Graph is the most fitting choice. This format enables straightforward comparison of student enrollment across the different streams.
The following data represents the income of a country for a year: 
Calculate the National Income (NI) of the country.