STP 231 Lecture Notes - Lecture 31: Zero 7, Blood Pressure, Nba Draft Combine
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Member of two populations have a natural pairing. Population 1: test scores for a group of students without tutoring. Population 2: test scores for the same group of students with tutoring. Paired t-test: assumptions: random and dependent samples, population of the differences is normally distributed. Paired t test: null and alternative hypotheses: ha: 1 - 2 < 0 or 1 < 2 --------> left tail test, 1 - 2 > 0 or 1 > 2 --------> right tail test. 1 - 2 0 or 1 2 -------> two tail test. D= 1 - 2: where d-bar = mean of the population differences. Confidence interval: where d-bar is the point estimate, d-bar = mean of pair differences, sd= standard deviation of the paired differences. Example: a researcher wanted to find the effect of a special diet on systolic blood. A researcher wanted to find the effect of a special diet on systolic blood pressure.