074 - 13/09/2007 09:00:00 Lower Quartiles = QL The median...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Statistics 13/09/2007 09:00:00 Measures of Variability Range = Largest value – Smallest value o Advantage: Easy to compute o Disadvantage: Only use two values WB7-1 o Sample A: Range = 510 – 485 = 25 o Sample B: Range = 1000 – 0 = 1000 Variance = “Average” squared deviation from the mean (7.2) sample variance = s squared Example WB7-1 Variance of Sample A: 112.5 Variance of Sample B: 205,000 (computations not shown) The numbers in both samples represent credit card balances in dollars Variances are measured in square units Sample Variance Formula #1 X Deviation (x-x) Squared Deviation 0 0 – 10 = -10 (-10)squared = 100 10 10 – 10 = 0 (0)squared = 0 20 20 – 10 = 10  (10) squared = 100 30 0 200 Sample Variance Formula #2 X Xsquared 0 0 squared = 0 10 10 squared = 100 20 20 squared = 400  30 500
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Quartiles
Background image of page 2
Background image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 13/09/2007 09:00:00 Lower Quartiles = QL The median of Minimum and the Median Upper Quartile = QU The median of Median and the Maximum Computing QL and QU Rank data in order from smallest (1) to largest (n) Find overall median QL = median of values ranked below the overall median QU = median of values ranked above the overall median Five-Number Summary: n even Ordered data: 1 2 3 4 5 6 Overall Median: (3+4)/2 = 3.5 QL = 2 / QU = 5 Five number summary: 1 , 2 , 3.5 , 5 , 6 Five-Number Summary: n odd Ordered data: 1 2 3 4 5 6 7 Overall Median: 4 QL = 2 / QU = 6 Five number summary: 1 , 2 , 4 , 6 , 7 13/09/2007 09:00:00...
View Full Document

This note was uploaded on 03/29/2008 for the course STAT 1200 taught by Professor Larryreis during the Fall '07 term at Missouri (Mizzou).

Page1 / 3

074 - 13/09/2007 09:00:00 Lower Quartiles = QL The median...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online