Question

how determine the class boundaries.
recall that we want the class boundaries to include all the whole numbers within that class, so the class with the limit 28 – 38 will have the class boundary 27.5 – 38.5.
notice that the boundaries extend half of a unit below the lower class limit and half a unit above the upper class limit.
complete the table.

class limits	class boundaries
39 – 49	38.5 – ____
50 – 60	____ – 60.5
61 – 71	60.5 – 71.5
72 – 82	71.5 – ____

Explanation:

Step1: For class 39 - 49

To find the upper class boundary, add 0.5 to the upper class limit (49). So, \( 49 + 0.5 = 49.5 \).

Step2: For class 50 - 60

To find the lower class boundary, subtract 0.5 from the lower class limit (50). So, \( 50 - 0.5 = 49.5 \).

Step3: For class 61 - 71

The lower class boundary is given as 60.5, and the upper class boundary is 71.5 (already provided, just confirm the pattern).

Step4: For class 72 - 82

To find the upper class boundary, add 0.5 to the upper class limit (82). So, \( 82 + 0.5 = 82.5 \).

Answer:

• For 39 - 49: 38.5 - 49.5
• For 50 - 60: 49.5 - 60.5
• For 61 - 71: 60.5 - 71.5 (the middle part is just a continuation, no new calculation here)
• For 72 - 82: 71.5 - 82.5

Filling the table:

• 39 - 49: \( 49.5 \)
• 50 - 60: \( 49.5 \)
• 61 - 71: (the blank is just part of the boundary, no new value needed as 60.5 - 71.5 is correct)
• 72 - 82: \( 82.5 \)