When a researcher uses the classes 129-147, 147-165, 165-183 to create a distribution, he is violating which of the following suggested practices?
Click on the arrows to vote for the correct answer
A. B. C. D.D
The classes are overlapping (for e.g., the classes "147-165" and "165-183" have the point "165" in common). There are no open-ended classes and the classes have the same class interval. Note that "Avoid a use of non-standard class marks" is a bogus choice; there is no such suggested practice.