W - 1: ILLUSTRATING MEASURES OF POSITION

• Statistics


  A branch of mathematics that deals with collecting, organizing, presenting, analyzing, and interpreting data to come up with useful and meaningful information
• Measures of Central Tendency

  • Mean
  • Mode
  • Median
• Data set


  • 2, 4, 4, 6, 9
• Mean


  The average of the data set
• Median


  The middle number of the data set
• Mode


  The value that occurs most often
• The mean of the data set 2, 4, 4, 6, 9 is 5
• The median of the data set 2, 4, 4, 6, 9 is 4
• The mode of the data set 2, 4, 4, 6, 9 is 4
• Quartiles


  The 3 score points which divide a distribution into 4 equal parts
• Deciles


  The 9 score points which divide a distribution into 10 equal parts
• Percentiles


  The 99 score points which divide a distribution into 100 equal parts
• Applying the concept of median to divide the data set into more equal parts of equal sizes results in partition values called quartiles, deciles, and percentiles
• Lower Quartile (Q1)


  The first quartile, 25% of the data set is below or equal to this value
• Median (Q2)


  The second quartile, 50% of the data set is below or equal to this value
• Upper Quartile (Q3)


  The third quartile, 75% of the data set is below or equal to this value
• Interquartile Range


  The range between the lower and upper quartiles
• The 3rd tallest student is Kenneth, shortest —>🧍🧍🧍🧍🧍🧍🧍|🧍|🧍🧍<— tallest. which means 70% of the students are shorter than Kenneth and 20% of the students are taller than Kenneth
• The 7th tallest student is Vincent, shortest —>🧍🧍🧍|🧍|🧍🧍🧍🧍🧍🧍<— tallest. which means 30% of the students are shorter than Vincent and 60% of the students are taller than Vincent
• EQUALITY QUARTILES DECILES PERCENTILES

  
  

  𝑸𝟏 = 𝑷𝟐𝟓

  25% 25%

  
  

  𝑸𝟐 = 𝑫𝟓 = 𝑷𝟓𝟎

  50% 50% 50%

  
  

  𝑸𝟑 = 𝑷𝟕𝟓

  75% 75%