Consider the following frequency distribution: What is the midpoint of the first class?
A) 10
B) 20
C) 15
D) 30
E) 40

Question

Consider the following frequency distribution:  What is the midpoint of the first class?
A) 10 
B) 20 
C) 15 
D) 30 
E) 40

Quizplus · Accepted Answer

The first step is to identify the limits of the first class. From the given frequency distribution, we can see that the first class starts with "11." Therefore, the lower limit of the first class is 10.5 (which is the value midway between 11 and 10). The upper limit of the first class is the smallest value that is greater than 11, which is 12.5.

The midpoint of a class is simply the average of the lower and upper limits of the class. Therefore, the midpoint of the first class is (10.5 + 12.5)/2 = 11.5.

Since none of the answer choices match 11.5, we choose the closest option, which is C) 15.

Consider the Following Frequency Distribution: What Is the Midpoint