median
don steward
mathematics teaching 10 ~ 16

Saturday, 28 January 2012

Thursday, 26 January 2012

translating English to algebra, relationships

see also other postings on expressions and equations

a ppt is here







translating English to algebra, expressions

an important part of students accommodating the conventions of written algebra
viewed as a kind of language

a ppt is here











Saturday, 21 January 2012

giant chairs

possibly using the average height graph (in feet)
1 foot = 0.3048 metres (30.48 cm)
















state how high off the ground you think the seats of these chairs are

















comparing two data sets

the longevity of US Presidents has interesting features

a powerpoint is here

many students will sensibly think that more recent Presidents lived to an older age on average  due to advances in health care, nutrition and other factors that have led to a (general) increase in life expectancy

some Presidents in this data set are not counted (but could be)
this is to keep the sizes of the data sets the same (with apologies) for a frequency graph comparison

the data sets


















a possible question to direct the study:




















the analysis could use some of the following techniques
which are overlapping in terms of what they tell you:






little point in estimating the means - just to practise this technique











Thursday, 19 January 2012

cumulative graph matching

match the cumulative frequency graph to the associated boxplot