2.6 Measures of Spread. Measures of Spread Measures or Spread Vs. Central Tendency.
Transcript of 2.6 Measures of Spread. Measures of Spread Measures or Spread Vs. Central Tendency.
2.6 Measures of Spread
Measures of Spread
• Measures or Spread Vs. Central Tendency
Deviation
• Deviate
• Deviation of population =
• Deviation of Sample
Standard Deviation
• A “cool” way of finding the average of the deviations.
• Ideas on how?
Population Standard Deviaiton
Sample Standard Deviation
Example
• Use means and standard deviations to compare the heights of the 2 basketball teams.
Falcons RavensPlayer Height (cm) Player Height (cm)Laura 183 Sam 166Jamie 165 Shannon 163Deepa 148 Tracy 168Colleen 146 Claudette 161Ingrid 181 Maria 165Justiss 178 Amy 166Sheila 154 Selena 166
Standard Deviation
Falcons Height Deviation, x-µ (x-µ)2
Laura 183 Jamie 165 Deepa 148 Colleen 146 Ingrid 181 Justiss 178 Sheila 154 SUM
Standard DeviationRavens Height Deviation, x-µ (x-µ)2
Sam 183
Shannon 165
Tracy 148
Claudette 146
Maria 181
Amy 178
Selena 154
SUM
Box and Whisker Plot
• Divided the data into 4 equal groups.
• Uses Medians
• 1st quarter, second quarter, third quarter, fourth quarter
Example
• A random Survey of people at a science-fiction convention asked them how many times they had seen Star Wars. The results are as follows.
3 4 2 8 10 5 1 15 5 16 6 3 4 9 12 3 30 2 10 7
• Make Box and Whisker Plot
Assignment
• Pg 148 #’s 1-3,6,7