PPGA 503 Statistic Final Exam Graded A+ 2023

t-test - ANSWER-a statistical test used to evaluate the size and significance of the difference between two means Different methods to compare means - ANSWER-ttest, chi test, binary variable - ANSWER-a variable having only two categories, aka. dichotomous response vs explanatory variable - ANSWER-Response variable is an outcome variable ABOUT which comparisons are made. Explanatory variable DEFINES the group. Ie. time spend on household work is the Response variable and gender is the explanatory variable. longitudinal study - ANSWER-longitudinal study observes subjects at several times, if they have the same subject every time they are called dependent samples. dependent samples. - ANSWER-two samples are dependent when a natural matching occurs between each subject in one sample and a subject in the other sample. Usually this hap pens when each sample has the same subjects OR if the 2 samples of the same category (ie husbands and wives in housework) independent samples. - ANSWER-MORE COMMON, This means that the observations in one sample are independent of those in the other sample. The subjects in the two samples are different, with no matching between one sample and the other sample Types of studies - ANSWER-Longitudinal (over time a long time, sometime with same subjects(dependant samples) ) Observational (comparison of groups often results from dividing samples into sub-samples. Cross-sectional uses a single survey to compare groups. p-value - ANSWER-The probability of getting a sample stat (that confirms the alt hypothesis) if the null hypothesis is true. Usually, you can reject the null if the p-value is less than 0.05. Type I Error - ANSWER-a " false positive". Type I error occurs when a researcher concluder that the independent variable had an effect on the dependent variable when in truth it did not. Type II Error - ANSWER-a "false negative". Type II error occurs when a researcher concludes that the independent variable had no effect on the dependent variable when in truth it did.