Zusammenfassung der Ressource
Statistics topics
- Cumulative Frequency
- CF charts
- Calculate CF by summing frequencies
- Plot at end of range
- Read off median, UQ, LQ, etc.
- They always go up, S -shape
- Box plots
Anmerkungen:
- http://www.gcsemathstutor.com/cumulativefreq.php
- Histograms
- Frequency (area) = Frequency Density (y-axis) x Column width (x-axis)
Anmerkungen:
- http://www.bbc.co.uk/schools/gcsebitesize/maths/statistics/representingdata3hirev3.shtml
- Find Median : half area either side
- find other % splits
- Describing / comparing data
- 1 point per mark
- Compare mean to mean, IQR to IQR, etc
- Outliers
- Bivariate data
- Scatter graphs
- Always draw a LOBF
- Find and interpret gradient and y-intercept
- Correlation
- Positive, negative, weak, strong, none
- Correlation does not imply causation
Anmerkungen:
- http://www.tylervigen.com/spurious-correlations
- Interpolation (within data) OK,
Extrapolation (outside range of
data) BAD
- Collecting data
- Survey -> Sample
Census -> Population
- Pros / cons of sampling
- Capture / Recapture
Anmerkungen:
- Stratified Sampling
- Grouped Data
- Discrete / continuous data
Anmerkungen:
- http://intellspot.com/discrete-vs-continuous-data/
- Easier to represent, but info is "lost"
- Find the mean
- Add the fx
column
- Frequency polygon
- Plot at MIDPOINTS, join
dot to dot, not to origin
- Find the median
- Total
frequency is n,
find the n/2 th
item
- Two way tables
- Don't forget to include TOTAL row and column
- Charts
- Bar Charts
- Pie Charts
- Limitation - totals not obvious
- Pictograms
- Vertical Line Charts
Anmerkungen:
- http://wtmaths.com/vertical_line_charts.html
- Discrete data
- Time Series