Math 15 – Elementary Statistics

Chapter 5 – Part 2Summarizing Data Numerically

Measuring Spread

Class A – 73, 74, 75, 76, 77Class B – 55, 65, 75, 85, 95

Measuring Spread

Class A – 73, 74, 75, 76, 77Class B – 55, 65, 75, 85, 95

Variance and Standard Deviation

Variance and Standard Deviation

Variance and Standard Deviation

Example

Example

Percentiles

Percentiles

Exam Scores –

32, 35, 43, 56, 66, 69, 73, 74, 75, 77, 78, 79, 80, 81, 83, 85, 87, 88, 92, 98

Median (50th percentile)

Quartiles (25th and 75th percentiles)

Percentiles

Exam Scores –

32, 35, 43, 56, 66, 69, 73, 74, 75, 77, 78, 79, 80, 81, 83, 85, 87, 88, 92, 98

90th percentile?

IQR and 5 – Number Summary

IQR and 5 – Number Summary

Outliers?

Yuck? What are you learning here?

Example

Arcata Real Estate – Described Numerically and Graphically!