Question 1: Given the class intervals 0-10, 10-20, 20-30, find the midpoints for each interval.

Answer: 5, 15, 25

Question 2: Plot the midpoints of the class intervals 0-10, 10-20, 20-30 on the grid above.

Answer: Students will draw points at 5, 15, 25 on the graph.

Question 3: A data set has class intervals 5-15, 15-25, 25-35. What are the midpoints?

Answer: 10, 20, 30

Question 4: Explain why midpoints are used when constructing a frequency polygon.

Answer: Midpoints represent the center of each class interval, providing accurate points for plotting frequency data.

Question 5: Construct a frequency polygon by plotting midpoints for the intervals 0-10, 10-20, 20-30, with frequencies 4, 7, 3. Show the points on the grid.

Answer: Plot points at (5,4), (15,7), (25,3).

Question 6: Given the following class intervals and frequencies: 0-10 (3), 10-20 (6), 20-30 (2). Calculate and plot the midpoints.

Answer: Midpoints: 5, 15, 25. Plot points at these midpoints with heights 3, 6, and 2 respectively.

Question 7: A chart shows class intervals 0-8, 8-16, 16-24. If the midpoints are plotted correctly, what are their coordinates assuming the frequencies are 5, 8, 4?

Answer: Points at (4,5), (12,8), (20,4).

Question 8: Identify the error in the following plotting: midpoints at 5, 15, 25 are plotted at heights 4, 7, 3, but the midpoint 15 is plotted at height 25.

Answer: The height should correspond to the frequency, not the midpoint value.

Question 9: Using the class intervals 2-12, 12-22, 22-32, with frequencies 3, 5, 2, compute midpoints and describe how you would plot them.

Answer: Midpoints: 7, 17, 27. Plot points at these midpoints with heights corresponding to frequencies 3, 5, 2.

Question 10: Challenge: Given class intervals 0-5, 5-10, 10-15, with frequencies 2, 4, 6, calculate midpoints and plot them. Then, draw the frequency polygon connecting these points.

Answer: Midpoints: 2.5, 7.5, 12.5. Plot points at these midpoints with heights 2, 4, 6, and connect with lines.