Question to answer in English language

12, 15, 18, 20, 20, 25, 28

Minimum value (Min) = 12
Maximum value (Max) = 28

The range is $\boxed{16}$ and the coefficient of range is $\boxed{0.4}$.

3. Find the mode of the following frequency distribution:

The modal class is the class with the highest frequency. Here, the highest frequency is 16, which corresponds to the class 20 - 30.

• Lower limit of the modal class ($L$) = 20
• Frequency of the modal class ($f_m$) = 16
• Frequency of the class preceding the modal class ($f_1$) = 13
• Frequency of the class succeeding the modal class ($f_2$) = 12
• Class width ($h$) = $30 - 20 = 10$

The mode of the frequency distribution is $\boxed{24.29}$.

4. Define primary and secondary data and What are the methods of collecting primary data?

• Primary Data: This refers to data collected directly from the original source for a specific research purpose. It is raw, first-hand information that has not been previously published or analyzed.

• Secondary Data: This refers to data that has already been collected by someone else and is available for use. It is second-hand information that has been processed, analyzed, or published previously.

• Methods of collecting primary data:

  • Direct Personal Investigation: The investigator collects data by directly interacting with the respondents.
  • Indirect Oral Investigation: Data is collected by interviewing third parties who have knowledge about the subject of inquiry.
  • Information through Local Correspondents: Local agents or correspondents are appointed in different areas to collect and transmit information.
  • Mailed Questionnaire Method: Questionnaires are sent to respondents via mail, who fill them out and return them.
  • Schedules sent through Enumerators: Trained enumerators visit respondents with a questionnaire (schedule) and fill it out themselves by asking questions.
  • Observation Method: Data is collected by observing the behavior or phenomena directly without direct interaction.
  • Experimentation Method: Data is collected through controlled experiments to study cause-and-effect relationships.

5. The mean of a set of 100 observations were found to be 50. On checking, it was found that two observations were wrongly taken as 32 and 15 instead of 82 and 51. Calculate the correct mean.

Given: Number of observations ($N$) = 100, Incorrect Mean = 50

Wrong values = 32 and 15
Correct values = 82 and 51

The correct mean is $\boxed{50.86}$.

**6. Seven methods of imparting business education were ranked by the BBS students of two campuses