Cumulative Frequency Graph

• What is the focus of the lesson discussed?

  Cumulative frequency graphs
• What should you do if you need basic information about drawing cumulative frequency graphs?

  Watch the video on drawing graphs
• What does the x-axis of the cumulative frequency graph represent?

  Weight loss
• What does the vertical axis of the cumulative frequency graph represent?

  Cumulative frequency
• What are the three things to find using a cumulative frequency graph?

  • Median
  • Lower quartile
  • Upper quartile
• Why are calculations for median and quartiles approximations in this context?

  Because the data is grouped
• How many people participated in the weight loss program?

  80 people
• How do you calculate the median from the cumulative frequency graph?

  80 divided by 2 equals 40
• What is the median value found from the graph?

  14
• How do you find the lower quartile from the cumulative frequency graph?

  80 divided by 4 equals 20
• What is the lower quartile value found from the graph?

  9
• How do you find the upper quartile from the cumulative frequency graph?

  80 divided by 4 times 3 equals 60
• What is the upper quartile value found from the graph?

  20
• How is the interquartile range calculated?

  Upper quartile minus lower quartile
• What does the interquartile range measure?

  Spread of the middle 50% of data
• What is an advantage of using the interquartile range over the range?

  It removes the effect of outliers
• What percent does the lower quartile represent?

  25 percent
• What percent does the upper quartile represent?

  75 percent
• What is the significance of the median in a cumulative frequency graph?

  It represents the middle value of data