Maths Calc

• Cumulative Frequency Graphs
• What is the focus of the lesson on cumulative frequency graphs?

  Finding median, lower quartile, upper quartile
• Why are calculations for median and quartiles approximations in group data?

  Because it is based on grouped data
• 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 is the lower quartile calculated in this context?

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

  9
• How is the upper quartile calculated in this context?

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

  20
• How is the interquartile range (IQR) calculated?

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

  Spread between 25th and 75th percentiles
• What is an advantage of using the interquartile range over the range?

  It removes outliers from the data
• What are the three key values found from the cumulative frequency graph?

  • Median: 14
  • Lower quartile: 9
  • Upper quartile: 20
• What is the process to find the median, lower quartile, and upper quartile from a cumulative frequency graph?

  1. Identify total number of data points.
  2. Calculate median: total/2.
  3. Calculate lower quartile: total/4.
  4. Calculate upper quartile: total * 3/4.
  5. Use the graph to find corresponding values.