Statistics Learning for Data Science-2 of N ( T test, Z test , F test)
Hypothesis Testing From http://www.statisticshowto.com/when-to-use-a-t-score-vs-z-score/ --- A z-score and a t score are both used in hypothesis testing. Few topics in elementary statistics cause more confusion to students than deciding when to use the z-score and when to use the t score. Generally, in elementary stats and AP stats , you’ll use a z-score in testing more often than a t score. T-score vs. z-score: When to use a t score The general rule of thumb for when to use a t score is when your sample size meets the following two requirements: The sample size is below 30 The population standard deviation is unknown (estimated from your sample data) In other words, you must know the standard deviation of the population and your sample size must be above 30 in order for you to be able to use the z-score. Otherwise, use the t-score. Note: You can estimate the population standard deviation, σ by using the standard deviation of the sample, s. However, you can only