PSY 350 Lecture Notes - Lecture 30: Standard Deviation, Psy, Central Limit Theorem
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Homework #3 is due monday 3/19 which is after break. Lecture: when and why to use a t-test. Distinguish the t distribution from the z distribution and choose which is more appropriate given a specific study context. Differentiate the three different kinds of t-tests t-tests. So far, we have used z-scores to compare a known sample mean with a known population mean. But we usually don"t know the population mean or the population standard deviation. And we know the population standard deviation is > the sample standard deviation. That"s why we use a corrected version of the standard deviation formula when working with a sample: *a t-score is just like a z-score, but uses the sample standard deviation instead. ***a t-score is more appropriate to use when we don"t know the population value. Standard deviation is the square root of the variance. Describe the number of scores in a sample that are independent and free to vary.
