Sampling Errors

Bootstrapping

• Although imperfect, each sample should give a reasonable picture of the population as a whole.
• In the real world, we usually only have one sample. We want to use this sample to estimate the population parameter. (make an inference)
• e.g. estimate the percentage of students at Kare Kare College
• who travel to school by car.
• Since the sample is representative of the population, we will re-sample from the sample (with replacement) to estimate the sample-to-sample variability ie sampling error or margin of error.
• Re-sampling from the sample is called Bootstrapping

“Opinion Divided on NZ-US exercises”

• Margin of error
• % who support resumption
• 95% CI:
• Meaning:
• Judgement: