Fill-in the blanks. Write your answer on the space provided. The number of times a particular observation appears in a data set is called its ___________________________. One way to display the spread of frequencies of the categories, values of a counting variable or class intervals is to construct a ____________________________. In a class interval, the middle score is called the ____________________________. The number of values may fall in a class interval is its _________________________. ___________________ are the values that occupy the gaps between class intervals. They can be found by subtracting 0.5 from the lower class limit and adding 0.5 to the upper class limit.​