From the following data, cumulative frequency for the class $20-30$ isClass | $0-10$ | $10-20$ | $20-30$ | $30-40$ | $40-50$---|---|---|---|---|---Freq | $4$ | $6$ | $20$ | $8$ | $3$

Divided bar chart is considered for

$Data are said to be ______ if the investigator himself is responsible for the collection of the data.$

A suitable graph for representing the portioning of total into sub parts in statistics is:

The average of salaries in a factory is $47,000$. The statement that the average salary $47,000$ is

$Statistics cannot deal with ______ data.$

$Census reports are used as a source of ______ data.$