Final answer:
The upper class boundary is calculated by adding 0.5 to the upper limit of the class interval. For the class interval 23-35, the upper class boundary is 35 + 0.5, which equals 35.5. Hence, the correct answer is option 4) 35.5.
Step-by-step explanation:
The question being asked is: What is the upper class boundary of the class 23-35? The four options given are 1) 7, 2) 7.5, 3) 35, and 4) 35.5.
To find the upper class boundary of a class interval in statistics, we typically add half of the gap between the upper limit of one class and the lower limit of the next class. This gap is called the class width. If we look at the example given in the class intervals from the research (Table 1.31 by Researcher A), we can see that each class width is 1 due to the consistent class limits (e.g., 0.5-6.5, 6.5-12.5).
Applying this concept to the class interval 23-35, we add 0.5 to the upper limit of 35 to find the upper class boundary. Therefore, the upper class boundary is 35 + 0.5 = 35.5, which means the correct answer is option 4) 35.5.