Margin of error

Bootstrapping

• The margin of error is half of the interval.

Central Limit Theorem

Margin of error of the mean

• 95%

• Approximately

Margin of error of a proportion

The greatest margin of error occurs when

Margin of error of a proportion

Rule of thumb becomes

Margin of error of a proportion

It should only be applied when the probability is between 0.3 and 0.7

Margin of error for differences

• If the results are from the same survey or poll:

• Margin error of difference = 2 x Margin of error of the Poll

Margin of error for differences

• If the results are from two independent surveys or polls:

• Margin error of difference = 1.5 x Average of error of each Poll