Now that you have all this information about descriptive statistics and probabilities, it is time to start inferential statistics. There are two branches of inferential statistics: hypothesis testing ...Now that you have all this information about descriptive statistics and probabilities, it is time to start inferential statistics. There are two branches of inferential statistics: hypothesis testing and confidence intervals. Definition \PageIndex1 Hypothesis Testing: making a decision about a parameter(s) based on a statistic(s). Definition \PageIndex2 Confidence Interval: estimating a parameter(s) based on a statistic(s).