### Inference

#### Understanding Inference

 STATISTIC METHODS TO MAKE AN INFERENCE EXERCISE RESOURCES Introduction:the comparative investigative question &the purpose of investigation REPORT WRITING FOR TEACHER Method:how to select a sample & collect data SIMPLE RANDOM SAMPLINGSTRATIFIED SAMPLINGCLUSTER SAMPLINGSYSTEMATIC SAMPLING Results:Draw a box plot using a stem-and-leaf diagram DRAW A BOX PLOT USING GEOGEBRA DRAW A BOX PLOT USING EXCEL Results:Work out some statistics (tendeny and spread) RANGE,QUARTILES AND MEDIANHOW MANY PEOPLE ABOVE MEDIANCOMPARING USING MEDIAN AND IQR Discussion:to make an inference or to answer your questions VARIATIONUNDERSTANDING CONFIDENCE INTERVALSWORKING OUT CONFIDENCE INTERVALS USING MARGIN ERROR FORMULACOMPARING BOX PLOTS Summary of the statistics cycle Task A Task B Task C Revision PRACTISE ASSESSMENT

Achievement Criteria

Achievement

• Use statistical methods to make an inference.

Achievement with Merit

• Use statistical methods to make an inference, with justification

Achievement with Excellence

• Use statistical methods to make an inference, with statistical insight.

Learning objectives  include:

• carry out investigations of phenomena, using the statistical enquiry cycle:

− using existing data sets

− evaluating the choice of sampling and data collection methods used

− using relevant contextual knowledge, exploratory data analysis, and statistical

inference

• make inferences from surveys:

− using sample statistics to make point estimates of population parameters

− recognising the effect of sample size on the variability of an estimate

in the Statistics

Methods involve:

• posing an appropriate investigative comparison question from a given set of

population data

• selecting random samples

• selecting and using appropriate displays and measures

• discussing sample distributions

• discussing sampling variability, including the variability of estimates

• making an inference

• communicating findings in a conclusion.