STAB22H3 Chapter Notes - Chapter 19-20: Sample Size Determination, Statistical Hypothesis Testing, Standard Deviation

• School: UTSC
• Department: Statistics
• Course: STAB22H3
• Professor: Mahinda Samarakoon

Document Summary

Standar error: calculated standard deviation of a sampling distribution. For a sample proportion, , the standard error is: se ( )= Ex. sample proportion of sea fans affected by the disease aspergillosis. A confidence interval is an estimate +/- margin of error. June "08, survey of 100 cdns found that 68% of canadians support gay marriage. Researchers reported margin o error to be +/- 3. 1%. Question: standard among pollsters is to use the 95% confidence level unless otherwise stated. If this polling were done repeatedly, 95% of all random samples would yield estimates that come within. 3. 1 percentage points (0. 031) of the true percentage (proportion) of all cdns who support gay marriage. The extent of the inteveal on either side of is called the margin o error (me). The more confident we want to be, the larger the margin of error must be. The most commonly chosen confidence levels are 90%, 95% and 99%