Join Eddie Davila for an in-depth discussion in this video Using probability trees, part of Statistics Foundations: Probability.
- Disease testing, … always nerve wracking for the patient. … The hope is for negative results. … But unfortunately some patients … will receive positive results indicating disease. … It's very scary. … But a doctor will likely retest … in the hopes that there was an error. … The hope that this first test was a false positive. … So what's the probability … that this first test might be wrong. … First, we need to realize … that we are considering two different events. … Event one disease or no disease. … Event two test positive or tests negative. … Next, we need some statistics. … According to doctors, … only one in 10,000 people has the disease. … This is helpful in evaluating event one. … Now for the stats on event two, … the testing company states … that those with the disease … will test positive 99% of the time. … But 1% of those with the disease will test negative. … That's a false negative also called a type two error. … How about the uninfected? … Well, 2% of uninfected patients …
Eddie explains that probability is used to make decisions about future outcomes and to understand past outcomes. He covers permutations, combinations, and percentiles, and goes into how to describe and calculate them. Eddie introduces multiple event probabilities and discusses when to add and subtract probabilities. He describes probability trees, Bayes’ Theorem, binomials, and so much more. You can learn to understand your data, prove theories, and save valuable resources—all by understanding the numbers.