Thursday, September 26 A word about notations – pp. 7 – 12. How to describe a distribution of values Data collection exercise Frequency distributions Histogram Frequency and percentage polygons Cumulative frequency polygons (ogive curve)

Population http://star.cde.ca.gov/star2001/district_index.html Please go to this url

Population µ Sample X _ _

Pick a school district that is not a high school district and does not appear to be a “special” district, e.g., a charter school, HomeSmartKids of Knightsen, etc.; beyond that, try to pick one randomly from the list. Report the following: 1. For noneconomically disadvantaged, Grade 2 and Grade 5 Reading Mean Scaled Score. 2. For economically disadvantaged, Grade 2 and Grade 5 Reading Mean Scaled Score.

until you have 20 or 30 intervals” “A good guideline is to have at least ten times as many observations as classes until you have 20 or 30 intervals”

The ogive gives you a good view of the relationship between scores and percentile rank.

Household Income by Language Group (Source: 1990 Census of Population and Housing)