Lesson 5: Variance

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September 6, 2015 at 10:11 pm  •  Posted in f15-busad265 by  •  0 Comments

Mon Sep 7

Review:

Presentation:

  • Variance
    • Percentiles and Quartiles
      • Position in data set = i = percentile * n
      • 50th Percentile = Median
      • Q1 = 25th Percentile
      • Q2 = 50th Percentile = Median
      • Q3 = 75th Percentile
      • Interquartile Range (IQR = Q3 – Q1)
    • Box Plots: video
      • Visualize variance
    • Standard Deviation: video
      • Calculate variance
    • Example
      • Data: {213, 345, 609, 73, 167, 243, 444, 524, 199, 682}
      • Calculate Q1, Q2, Q3, IQR
      • Calculate standard deviation

Activity:

  • Use Data set 1 and 2 below
    • Data set 1: {2, 4, 8, 4, 6, 2, 7, 8, 4, 3, 8, 9, 4, 3, 5}
    • Data set 2: {7, -2, 5, 9, 0, -3, -6, -7, -4, -5, 2, -8}
  •  Calculate the following
    • Q1, Q2, Q3, IQR for each data set, separately
    • Draw Box Plots side by side for comparison
    • Calculate mean and standard variation, separately

Assignment:

  • Using Sheets and the D60-D70 % Free-Reduced Lunch data
    • Calculate Q1, Q2, Q3 and IQR (for D60 and D70, separately)
    • Draw Box Plots side by side for comparison
    • Calculate standard variation

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