In a frequency distribution, the first class interval begins at 18.The midpoint of the first class interval is 19.5, and the midpoint of the last class interval is 49.5.How many class intervals are there?
A)11
B)17
C)22
D)33
E)34

Question

Quizplus · Accepted Answer

The difference between the midpoint of the first class interval and its lower limit is 1.5 (19.5 - 18), which means the class width is 3 (since the midpoint is exactly in the middle of the class interval). The difference between the first and last midpoints is 49.5 - 19.5 = 30. Dividing this range by the class width (30 / 3) gives 10 intervals, but since we start counting from the first interval, we add 1 to get a total of 11 class intervals.

In a Frequency Distribution, the First Class Interval Begins at 18.The