Intro to Probability & Stats

  1. True or False?

    The sum of all class frequencies is equal to the size of the data set.
  2. True
  3. True or False?

    The cumulative frequency always increases from lower to higher classes
  4. True or False?

    A class frequency cannot be equal to zero.

    • It may be equal to zero if none of the scores fall
    • into a certain class. However, if the upper class turns out empty, it
    • means that the class width was chosen incorrectly: it's is too large.
  5. How do we define the class width while arranging a data set in classes?
    The data range (maximum minus minimum) is divided by the number of classes. The quotient can be rounded UP and never down.
  6. If the calculated class width is a decimal, how do we round it off?
    • We round it only UP. If the class width turns out a whole number,
    • increase it by 1; otherwise, the upper class will be wider than the
    • other classes.
  7. True or False?

    The lower limit of the lowest class must be equal to the smallest number in the data set.

    It may be even smaller, if that is convenient.
  8. True or False?

    The class midpoint is midway betweeen the lower and the upper limit of the same class.
  9. True or False?

    For a given data set and given number of classes, there still may be a variety of class distributions.

    You still can vary the class width and the lower limit of the lowest class.
Card Set
Intro to Probability & Stats
A basic interactive activity created by the instructor for memorizing key concepts learned in Chapter 2, week 2