Quartiles, interquartile range, box & whisker diagrams

• What concepts are covered in this video?

  Quartiles, interquartile range, box and whisker diagrams
• In which course and topic are these concepts found?

  AI course, topic 4 stats and probe
• What is the height of the shortest player in the basketball squad?

  160 centimeters
• How many players are in the basketball squad?

  10 players
• What is the height of the second shortest player?

  177 centimeters
• What is the height of the tallest player?

  205 centimeters
• What is the range of heights in the basketball squad?

  45 centimeters
• How is the range calculated?

  Maximum height minus minimum height
• Why might the range not be descriptive of the data?

  It is influenced by outliers
• What is the interquartile range (IQR)?

  Range excluding very small or large numbers
• What are the two quartiles identified in the data set?

  Lower quartile (Q1) and upper quartile (Q3)
• How do you find the median in an even data set?

  Average of the two middle numbers
• What is the median height of the basketball squad?

  181 centimeters
• What is the lower quartile (Q1) for this data set?

  177 centimeters
• What is the upper quartile (Q3) for this data set?

  185 centimeters
• How many quarters does the data set break into after identifying quartiles?

  Four quarters
• How is the interquartile range (IQR) calculated?

  Upper quartile minus lower quartile
• What is the interquartile range (IQR) for this data set?

  8 centimeters
• Why is the IQR a better descriptor for the middle players?

  It excludes outliers from the calculation
• What are the five key pieces of information for a box-and-whisker diagram?

  Minimum, lower quartile, median, upper quartile, maximum
• How do you draw a box-and-whisker diagram?

  Overlay lines for five key values
• What does each region in a box-and-whisker diagram represent?

  25% of the data
• What is the process for finding quartiles in a data set?

  1. Identify the median of the data set.
  2. Split the data into lower and upper halves.
  3. Find the median of the lower half (Q1).
  4. Find the median of the upper half (Q3).
• What are the steps to create a box-and-whisker diagram?

  1. Identify the minimum value.
  2. Identify the lower quartile (Q1).
  3. Identify the median.
  4. Identify the upper quartile (Q3).
  5. Identify the maximum value.
  6. Draw the diagram using these values.