2008+PCK+statistics+2009

The first activity involved working out what the particular variables were for a given set of data. Data cards ([|updatedschool.xls]) were provided along with the 2009 CensusAtSchool [|survey questions]. Information about the variables and the population [|KarekareCollege.doc]. To make the data cards up, print so there are two pages to one A4 sheet. Copy female cards onto one colour paper/card and male cards onto a different colour paper/card. This gives the 13th variable - gender.
 * 1. Problem/Plan

Links to other data cards: kiwi data cards scroll down page 27 August workshop; year 5-10 data cards in data and dots; a set of year nine data on this page also under growing scatterplots; neck/wrist and height/armspan data cards 14 May workshop

Some of the summary investigative questions posed at the workshop. What is the ethnic breakdown of this group? What are typical fitness levels for these students? What are typical popliteal lengths for these students? What are typical bag weights for these students? In general what do these bags weigh?

Summary investigative question selected: **What are typical popliteal lengths for these students?** || A handful of students was selected from the population by each group. || Plots were made by placing the data cards onto the provided grid. [|gridpopliteallesson4.doc] The A4 page needs to be enlarged to A3, and then the A3 enlarged to A3 again and joined. Graphs for different groups were compared. Similarities and differences were noted. Descriptions were made, with the prompt to comment on shape, spread, middle group and anything unusual.
 * 2. Data
 * 3. Analysis

Looked at writing some descriptions and then reflecting on them and improving them. Eg //italics is the original description// following is the updated description //Our sample contains 32 girls and 34 boys.// For Yr9 In this group we have 32 girls and 34 boys. For Yr10 This sample contains 32 girls and 34 boys.

//Values go from 11 to 90 cm.// The popliteal lengths for these students go from 11cm to 90cm.

//The most common popliteal length of 41cm is shared by 7 students.// The most common popliteal length is 41cm. 7 students have this length.

//The graph is more skewed to the right?// Popliteal lengths are right skewed for these students.

The popliteal lengths of this group ranges from 21 to 69cm.

//For this particular group the popliteal length is more clustered from 38cm to 50cm.// For these students the popliteal length is more bunched from 38 to 50cm.

//We have an unusual popliteal length of 122cm.// One student has a popliteal length of 122cm. We suspect this is an error.

We had seven popliteal lengths that were obviously incorrect. Because they were too small or too big. (10-17)

//The shape was normalish.// The popliteal lengths for these students appear to be approximately symmetrical.

//The middle group is between 40-53.// The middle group of popliteal lengths is between 40-53cm.

//This group of data forms a rectangular shape with tails on either side. The rectangle is spread from 38 to 49cm. This represents the majority of values. The range is from 32 to 65cm.// For these students the popliteal lengths are more bunched from 38 to 49cm. The popliteal lengths are right skewed for these students. The popliteal lengths range from 32 to 80cm. || A sample of 30 girls and a sample of 30 boys was selected. This was easy to do as the cards were coloured by gender. The data was graphed as a dot plot, using the smaller A4 sheet grid. Boys and girls plotted on the same axes, but two different dot plots. Middle 50% was circled with lines extending from circle to extremes. Descriptions made. Comparisons between groups made. Sparked another question about impact of whole school.
 * 4. From this exploration the question came up about whether there was a difference between girls and boys. A new comparison investigative question was posed. **At Karekare College, do boys popliteal lengths tend to be longer than girls popliteal lengths?**

Explored new investigative question. **At Karekare College, do year 10 boys popliteal lengths tend to be longer than year 10 girls popliteal lengths?** A sample of 30 year 10 boys and 30 year 10 girls was selected and dot plots made on a new grid. From here the middle was found, then the middle of the each half (lower and upper quartiles) and the box plot was made. Descriptions made, extending the range of comments. Group's graphs were compared and contrasted. A feeling for what might be true for the population was discussed.

New question: **At Karekare College, do students who walk to school tend to take less time to get to school than students who take the bus?** A sample of 30 students who walked and 30 students who came by bus were selected. The data was sorted and box plots were drawn on OHTs [|OHTtime.doc] so that they could be stacked up to compare. OHT for height [|OHTheight.doc] could compare boys and girls OHT for bag weight [|OHTbagweight.doc] could compare seniors and juniors ||