PHYSICS 102 Lecture Notes - Lecture 8: Exploratory Data Analysis, Quartile
Document Summary
Left digit is stem and right digit is leaf. In our example, sample size, n = 16. Median is in 8. 5th position i. e. (16+1)/2 = 8. 5. Median divides data into lower half and upper half quartiles further subdivide data. Quartile location is median location (rounded down) + 1. Median position was 8. 5 and therefore quartile location = (8+1)/2 = 4. 5. In our example median position was 8. 5 quartile location = (8 + 1)/2 = 4. 5. Lower quartile (q1) is 4. 5th position from lowest value i. e (4th value + 5th value)/2. Q1 = (10. 1 + 12. 7)/2 = 11. 4 minutes. Upper quartile (q3) is 4. 5th position from highest value i. e. (12th value + 13th value)/2. Q3 = (17. 7 + 18. 3)/2 = 18. 0 minutes. Outliers are values untypical of the bulk of the data. Check in case there has been a recording error (possibly correct it or discard it).
