Survey of rice varieties in Sri Lanka

Proportion using 'Old' varieties is p  =  17/36  =  0.472

Simulation of n = 36 from popn with π = 0.472

Use this simulation to introduce the ideas of a simulation providing the standard error for an estimator.

A simulation is unnecessary for this example — we can find the standard error (and bias) from the binomial distn.

Click Accumulate and take about 100 samples. Observe that the estimates could be in error by as much as 0.2.

Click Estimate s.e. and bias.

The bias and SE should be close to those from theory (bias = 0 and SE = 0.0832)


As part of a survey of rice producers in Sri Lanka, 36 farmers were randomly selected from 4 villages. Each sampled farmer was asked about the variety of rice that he used and the varieties were categorised as 'Old', 'Traditional' or 'New'. The 36 categorical values are described by the following frequency table.

Old varieties    17
Traditional varieties    15
New varieties 4
Total farmers    36