Which of the following best describes a frequency distribution A frequency distribution is a grouping of:（） A: data into intervals (classes) so that the number of observations in each of the non - overlapping intervals (classes) can be seen and tallied. B: selected data into intervals (classes) so that the number of observations in each of the non - overlapping intervals (classes) can be seen and tallied. C: dependent intervals (classes) so that they can be seen and tallied.

Which of the following statements about statistical concepts is FALSE（） A: A frequency distribution is a tabular display of data summarized into a relatively small number of intervals. B: An interval is a set of return values within which an observation falls. C: A sample contains all members of a specified group, but a population contains only a subset.

The data collected by the statistical survey can be original data or secondary data. The relationship between the original data and secondary data is ( ) A: The original data comes from the grass-roots units, and the secondary data comes from the superior units B: Secondary data is processed from original data C: There is no necessary connection between the original data and the secondary data D: There is no difference between primary data and secondary data

The number of class intervals in a frequency distribution is usually between ___________.

In general, grouped frequency distributions should have between 5 and 15 class intervals.